Hero's Trail: Create Your Own Action-Adventure Game In 30 Minutes


Hero's Trail: Create Your Own Action-Adventure Game In 30 Minutes

Overview

Hi there! In this tutorial we'll use the Hero's Trail template to create our own action-adventure game. We'll add coins, a sword attack, and the ability to defeat enemies.

We'll customize the project so you can truly make Hero's Trail your own.

At the end, we'll upload our game to GX.games so you can share it with your friends and the rest of the world!


Let's start by creating the project!

Creating Your Project

We'll use the Hero's Trail template as a starting point for our game.

  1. When you open GameMaker, click on "New" to see the Template menu.

  2. Then select the "Hero's Trail Base" (TUTORIAL) project.

  3. Enter your project name and hit "Let's Go!".

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This will open your new project where you can modify the template and play it. To play the game you can click on the undefined Run button at the top, or press F5 on your keyboard:

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This will open up your game, where you can hit “Play” and move around the level using the arrow keys:

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This is the base project that we'll build upon to create our own fully featured action-adventure game!


The GameMaker Window

Your project will open in GameMaker, which is divided into two sections:

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The Asset Browser is where you will create assets (such as objects, sprites, etc.) and the Workspace is where you will edit those assets to make them your own.

Let's go ahead and start using assets!


Adding Coins

Currently, our level is empty besides some baddies hunting the hero down... Let's give him something to loot!

We're going to add coins to the game: you will be able to place coins in the level and pick them up as the player:

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How Will This Work?

We'll create an object asset for the coin, which we can place in a level as many times as we want.

We'll program collisions between the player object and the coin object, so when the player touches a coin, the coin disappears.


Let's make the coin object!

We'll start by adding a new Object asset:

  1. Open the “Objects” group in your Asset Browser and select the “Game” group within it.

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  2. Click on the undefined “Create Asset” button at the top and double-click on “Object”.

    (Alternatively, you can click on "Objects" once and then hit “Create”.)

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  3. This will create a new Object asset inside your selected group, and open its Object Editor window in your workspace.

    Change its name to obj_coin:

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  4. The project already contains a coin sprite that we can use for this object. (If you want to import your own, go ahead!)

    In the Object window, click where it says  “No Sprite” to open the Asset Explorer.

    Open “Sprites”, then “Items” and select spr_coin.

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What did we just do?

We created a new object asset, and assigned a sprite asset to it, which is simply an image.

This way the coin sprite (spr_coin) will always appear on the coin object (obj_coin).


Placing Coins

Our coin object is ready! You can now open the first room (rm_level_1) and start placing coins.

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Doing so will open the Room Editor, which has many layers for you to place different kinds of assets.

First of all, make sure that the “Instances” layer is selected:

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This layer is where you place objects.


Now you can drag the coin object from the Asset Browser into the room! You can also hold Alt and place coins simply by clicking and holding (make sure that obj_coin is selected).

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There is only one coin object.

But, we can place it many times into the room!

Each coin placed in the room is known as an "instance". From one object, you can create many instances.


Customization!

Craft the hero's trail by placing coins and barrels in his path.
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Collecting Coins

We want the player to collect a coin on touching it. To make this work, we’ll make use of Events and Actions.

Events are placed inside Objects. GameMaker decides when a certain event runs (once, or every frame, or when a key is pressed, etc.)

Actions are placed inside Events. Each action has a unique purpose and effect.

You can add actions inside an event, and when GameMaker runs that event, all actions inside it are executed. This is how you program your objects!

But what are Events and Actions?!

Let's say you have a recipe for pancakes, with all the steps in a list...

  1. Whisk ingredients
  2. Heat a pan
  3. Pour batter
  4. Flip

In this case, your recipe is the event and these steps are the actions.

When you start following a recipe, you have to follow all steps inside it; only then the recipe is considered finished.

Similarly, when an event runs, all of the actions inside it are executed.

That is basically how you program an object in GameMaker -- you create a bunch of recipes with steps to control what your object does!


Let's program our coin!

We’ll do the following to program our coins to be collectable:

  1. Open obj_coin. If the Events window is closed, click on the “Events” button to open it:

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  2. Click on “Add Event”. This will open a list with all events (recipes) that you can add into your object.

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  3. Go under “Collision”. This opens an asset list and lets you select an object to “collide” with.

  4. Navigate to “Objects”, then “Game” and here, select obj_player.

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When you have chosen your event, you will be asked to choose between GML Visual and GML Code:

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Select GML Visual, and make sure to enable "Don't ask again for this project". Hit "OK".

Doing this will add the event to your object and open it in a new window. This is where you can start creating your recipe, to tell GameMaker what should happen when the coin touches the player.

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The new event window will mostly be empty, except for the panel on the right: the Toolbox.

The Toolbox

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The Toolbox will be your most important tool for programming objects. It contains all the actions that you can use, and allows you to search through them using the “Search...” field at the top.

Going back to the pancake analogy, the Toolbox contains all the possible steps that your recipe can contain -- whisk, pour, heat, flip, etc. -- and they can be placed into your recipe in whatever order you like!


Destroying the Coin

We are inside a collision event with the obj_player object. This means that the event will run when the coin touches a player, and all actions inside it will run too.

When that happens, we want the coin to be removed from the room. We’ll do the following to achieve that:

  1. In the Toolbox, search for the “Destroy Instance” action. Drag that action into the event.

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  2. Search for the “Do Effect” action and drag it into the event as well.

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The first action will destroy the coin instance, removing it from the room. The second action will create a particle effect for some eye candy.

For the “Do Effect” action, use the same settings as shown in the following image:

Destroy Instance, Do Effect: Flare, Above Objects, Medium, Relative, Relative, Yellow

Make sure to enable the "Relative" checkboxes for X and Y, as that makes sure that the effect appears at the coin's position.

You can select the “Do Effect” action and press F1, which will take you to its manual page. There you can read more information about its options in detail!

Run the game, and you will see that the player is now able to collect coins!

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Customization!

Change the effect that appears when you collect a coin, in obj_coin's collision event.

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You can change the Size too!

GameMaker has many types of effects that you can use, some of which are shown below:

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Increasing Coins Value

Although you can now collect coins, you will notice that the coin counter at the top does not change. This is because we are not actually changing the player’s coins variable.

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What's a Variable?

Let's go back to the pancake recipe.

At the top of the recipe page, let's say you have written:

    Bananas = 1

Throughout the recipe you will now remember how many bananas you have to add, just by reading that text!

If you are feeling more hungry for bananas today because you watched a documentary on cute monkeys, you can increase that count...

    Bananas = 3

…and you now have two more bananas in your recipe!

In this case, 'Bananas' is a variable.

It essentially stores a value and can be changed. We can easily create and modify variables like these in our code, so we know exactly how much we have of something!


The 'coins' variable

Our player object already contains a variable called coins, which stores the amount of coins it has. We simply need to increase this value when a coin is collected.

We previously added a collision event in obj_coin, so it could collide with obj_player. Now, we’ll add a collision event in obj_player, so it can collide with obj_coin and increase its own coins value.

  1. Open obj_player. In its “Events” window, add a collision event with obj_coin.

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  2. In this event, add the “Assign Variable” action. This action is used to change the value of a variable.

    (Refer to this section for instructions on adding actions from the Toolbox.)

Use the following settings for the “Assign Variable” action:

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Here, we’re assigning 1 to the coins variable. However, this will not simply set the variable to 1, because we’ve enabled the “Relative” option. This means that the value of “coins” will increase by 1, hence adding one coin!

Run the game now, and you will notice that the coin counter actually goes up when you collect a coin!

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Our game now has coins that can be placed anywhere and collected by the player to increase their score!


Adding a Sword

Currently the player can't attack at all, so we'll make it able to swing a sword so it can defeat any enemies in the way!

How Will This Work?

We'll create a new object that will show a sword slashing animation.

Whenever the player presses Space, this sword object will be displayed.

When an enemy touches this sword object, it will be defeated.

The project contains a sprite called spr_sword_attack. This is what will be displayed over the player when the Space key is pressed, creating an attack:

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Let’s start by creating an object for this.

  1. Open the “Objects” group, then select the "Game" group and create a new Object asset. Name this obj_sword_attack.

  2. Set its sprite to spr_sword_attack. You can find this sprite in the “Sprites” group under "Player".

    You can also drag it from the Asset Browser and drop it into the Sprite section of the Object:

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  3. Refer to this section for instructions on creating objects.


One-Time Instance

Instances, by default, exist permanently in a room until they are manually destroyed. For example, if you place a coin in the first level, it will remain there until the player touches it.

This sword object will be created by the player, but we don’t want it to keep existing. We want it to destroy itself when its animation ends. This ensures that after pressing space once, the sword also appears only once.

We’ll do the following to implement this behaviour:

  1. In the new obj_sword_attack object, click on “Add Event”, go under “Other” and select “Animation End”.

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  2. This event runs when the instance’s animation has ended. When this happens, we want it to destroy itself.

  3. Search for “Destroy Instance” in the Toolbox and drag it into the event.

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Our sword object is now ready: whenever it’s created by another object, it will only play once and then destroy itself.


Swinging the Sword

Let’s now allow the player to swing this sword when they press Space. We’ll do the following to achieve this:

Tip: You can press CTRL + T (or CMD + T on macOS) to open the “Go To” menu. This allows you to write the name of an asset (e.g. obj_player) and quickly jump to it!

  1. Go into obj_player.

    Click on “Add Event”, go under “Key Pressed” and select “Space”.

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  2. This event will run when the Space key is pressed. Holding the key will not do anything - to run the event a second time, it has to be released and then hit again.

  3. Add the “Create Instance” action from the Toolbox. This action is used to create a new instance of an object.

  4. Then, add the “Assign Variable” action. We’ll use this to change the horizontal scale of the sword (to make it face left or right based on the player).

Use the following settings for both actions:

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Each instance has an ID, which can be used to access it and modify its properties. In the “Create Instance” action, we have the “Target” option which holds the variable name that will store the ID. Since we’ve enabled “Temp”, this variable will be temporary.

Temporary variables only exist for the current event. After the event ends, a temporary variable is removed from memory.

The X scale of an instance controls its horizontal size, and it’s stored in the image_xscale variable. This variable is used by the player to flip its horizontal sprite, so that it looks left or right depending on the input:

image_xscale = -1 (Flipped)image_xscale = 1 (Default)
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This same scale will now also be applied to the sword, so it faces left or right depending on where the player is facing. To achieve this, we’re using the “Assign Variable” action to set sword.image_xscale equal to image_xscale.

sword.image_xscale

=

image_xscale

This is the sword’s X scale. Its image_xscale variable is accessed using a dot (".") through the sword variable, which stores the instance ID.


This is the player’s own X scale.

Run the game and you will now be able to swing the sword horizontally!

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Making the sword swing in all 4 directions is covered in another part as it's a longer process.


Defeating Enemies

We’ll now let the player defeat enemies by hitting them with the sword. Let’s do the following:

  1. In the Asset Browser, go into “Objects”, then “Game” and open “Enemies”.

  2. This group contains an object called obj_enemy_parent. This is a “parent” object for all enemies (currently it has only one "child": obj_baddie). Any events added to this object will automatically be applied to all enemies.

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  3. Open obj_enemy_parent and add a collision event with obj_sword_attack. This will run when the enemy touches the player’s sword (you know what's going to happen then!).

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  4. In this event, add a “Destroy Instance” action and a “Do Effect” action. These are the same actions we used in obj_coin to destroy it on colliding with the player!

    Since we have used these actions recently, you should be able to find them in the "Recently Used" section of the Toolbox, so you don't have to search for them again.

Use the following settings for these actions:

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Customization!

You can change the "Type" used in "Do Effect", to create a different type of effect when an enemy is defeated.

You can even place multiple Do Effect actions to create various effects at the same time! Go ahead, give it a go.

When an enemy comes in contact with the sword, it will now destroy itself and create a particle effect. Even though we have not added this event into obj_baddie, it will still apply to it because it’s a child of obj_enemy_parent:

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A child object does whatever its parent does.


Run the game and you will now be able to defeat enemies by swinging your sword! We've got some real power now!

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Optional Customization: RARE Coin!

GameMaker is based around objects, and to add new functionality to your game you simply make new objects and add/edit events!

For example: Create a second, rarer coin! Select obj_coin and hit CTRL+D to duplicate it (or do it through the right-click menu).

Name this new object obj_coin_rare.
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In its Create event, change its colour to red so it looks different!
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In obj_player, add a collision event with your new object, so when you touch the rare coin, you get 5 coins (or any other amount you like!):
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Now place it in your level and reward your player for exploring!
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It will look red in the game only, not in the Room Editor, as it requires its Create event to be run for the colour to change.


You have now created your own action-adventure game and have customized it in your own way!

Now follow the next part, or continue reading the bonus part below to publish your game to GX.games so you can share your creation with your friends and family.


Publish to GX.games

Publish your game to GX.games for free, and share your creation with your friends and family.


Summary

We created our own game from Hero's Trail, by adding a coins functionality and allowing the player to attack baddies. Here is a summary of what we've learned:

  • Events contain actions, similar to how recipes contain steps

  • Objects can collide with each other using collision events

  • Variables store values and can be increased/decreased using the "Relative" option in "Assign Variable"

  • Pretty particle effects can be created using the "Do Effect" action

  • Instances can be flipped using the image_xscale variable

  • Games can be uploaded easily to GXC from within GameMaker


We’re not stopping here -- in the next part, we’ll understand GameMaker works, and then add interactive level design by making chests, gates and more!


-> Continue to Understanding GameMaker

-> Skip to Interactive Level Design

<- Go back to index page