Your First Game¶
This tutorial will guide you through making your first Godot Engine project. You will learn how the Godot Engine editor works, how to structure a project, and how to build a 2D game.
This project is an introduction to the Godot Engine. It assumes that you have some programming experience already. If you’re new to programming entirely, you should start here: Scripting.
The game is called “Dodge the Creeps”. Your character must move and avoid the enemies for as long as possible. Here is a preview of the final result:
- Why 2D?
- 3D games are much more complex than 2D ones. You should stick to 2D until you have a good understanding of the game development process.
Launch Godot and create a new project. Then, download
dodge_assets.zip - the images and sounds you’ll be
using to make the game. Unzip these files in your new project folder.
For this tutorial, we will assume you are already familiar with the Godot Engine editor. If you haven’t read Scenes and nodes, do so now for an explanation of setting up a project and using the editor.
This game will use “portrait” mode, so we need to adjust the size of the
game window. Click on Project -> Project Settings -> Display -> Window and
Organizing the Project¶
In this project, we will make 3 independent scenes:
HUD, which we will combine into the game’s
scene. In a larger project, it might be useful to make folders to hold
the various scenes and their scripts, but for this relatively small
game, you can save your scenes and scripts in the root folder, which is
referred to as
res://. You can see your project folders in the Filesystem
Dock in the upper left corner:
The first scene we make defines the “Player” object. One of the benefits of creating a separate Player scene is that we can test it separately, even before we’ve created the other parts of the game.
To begin, click the “Add/Create a New Node” button and add an Area2D node to the scene.
Area2D we can detect other objects that overlap or run into the player.
Change its name to
Player. This is the scene’s “root” or top-level node.
We can add additional nodes to the player to add functionality.
Save the scene (click Scene -> Save, or press
In this project, we will be following the Godot Engine naming
conventions. Classes (Nodes) use
CapWords, variables and
snake_case, and constants use
Click on the
Player node and add an AnimatedSprite node as a
AnimatedSprite will handle the appearance and animations
for our player. Notice that there is a warning symbol next to the node.
AnimatedSprite requires a SpriteFrames resource, which is a
list of the animation(s) it can display. To create one, find the
Frames property in the Inspector and click “<null>” ->
“New SpriteFrames”. Next, in the same location, click
<SpriteFrames> to open the “SpriteFrames” panel:
On the left is a list of animations. Click the “default” one and rename it to “right”. Then click the “Add” button to create a second animation named “up”. Drag the two images for each animation into “Animation Frames” side of the panel:
Finally, add a CollisionShape2D as a child
Player. This will determine the player’s “hitbox”, or the
bounds of its collision area. For this character, a
gives the best fit, so next to “Shape” in the Inspector, click
“<null>”” -> “New CapsuleShape2D”. Resize the shape to cover the sprite:
Remember not to scale the shape’s outline! Only use the size handles (red) to adjust the shape!
When you’re finished, your
Player scene should look like this:
Moving the Player¶
Now we need to add some functionality that we can’t get from a built-in
node, so we’ll add a script. Click the
Player node and click the
“Add Script” button:
In the script settings window, you can leave the default settings, just click “Create”:
If this is your first time encountering GDScript please read Scripting first.
Start by declaring the member variables this object will need:
extends Area2D var SPEED = 400 # how fast the player will move (pixels/sec) var velocity = Vector2() # the player's movement vector var screensize # size of the game window
_ready() function is called when a node enters the scene tree, so
that’s a good time to find the size of the game window:
func _ready(): hide() screensize = get_viewport_rect().size
Now we can use the
_process() function to define what the player will do.
_process() function is called on every frame, so we’ll use it to update
elements of our game which we expect to be changing often. Here we’ll have it:
- check for input
- move in the given direction
- play the appropriate animation.
First, we need to check the inputs - is the player pressing a key? For this game, we have 4 direction inputs to check. Input actions are defined in the Project Settings under “Input Map”. You can define custom events and assign different keys, mouse events, or other inputs to them. For this demo, we will use the default events that are assigned to the arrow keys on the keyboard.
You can detect whether a key is pressed using
Input.is_action_pressed(), which returns
true if it is pressed
false if it isn’t.
func _process(delta): velocity = Vector2() if Input.is_action_pressed("ui_right"): velocity.x += 1 if Input.is_action_pressed("ui_left"): velocity.x -= 1 if Input.is_action_pressed("ui_down"): velocity.y += 1 if Input.is_action_pressed("ui_up"): velocity.y -= 1 if velocity.length() > 0: velocity = velocity.normalized() * SPEED $AnimatedSprite.play() else: $AnimatedSprite.stop()
We check each input and add/subtract from the
velocity to obtain a
total direction. For example, if you hold
the same time, the resulting
velocity vector will be
(1, 1). In
this case, since we’re adding a horizontal and a vertical movement, the
player would move faster than if it just moved horizontally.
We can prevent that if we normalize the velocity, which means we set
its length to
1, and multiply by the desired speed. This means no
more fast diagonal movement.
If you’ve never used vector math before (or just need a refresher) you can see an explanation of vector usage in Godot at Vector math. It’s good to know but won’t be necessary for the rest of this tutorial.
We also check whether the player is moving so we can start or stop the AnimatedSprite animation.
Now that we have a movement direction, we can update the player’s position
clamp() to prevent it from leaving the screen:
position += velocity * delta position.x = clamp(position.x, 0, screensize.x) position.y = clamp(position.y, 0, screensize.y)
Clamping a value means restricting it to a given minimum/maximum range.
Click “Play the Edited Scene. (F6)” and confirm you can move the player around the screen in all directions.
Now that the player can move, we need to change which animation the
AnimatedSprite is playing based on direction. We have a “right”
animation, which should be flipped horizontally (using the
property) for left movement, and an “up” animation, which should be
flipped vertically (
flip_v) for downward movement.
Let’s place this code at the end of our
if velocity.x != 0: $AnimatedSprite.animation = "right" $AnimatedSprite.flip_v = false $AnimatedSprite.flip_h = velocity.x < 0 elif velocity.y != 0: $AnimatedSprite.animation = "up" $AnimatedSprite.flip_v = velocity.y > 0
Play the scene again and check that the animations are correct in each of the directions.
Preparing for Collisions¶
We want the player to detect when it is hit by an enemy, but we haven’t made any enemies yet! That’s OK because we’re going to use Godot’s signal functionality to make it work.
Add the following at the top of the script (after
This defines a custom signal called “hit” that we will have our player
emit (send out) when it collides with an enemy. We will use the Area2D to
detect the collision. Select the
Player node and click the “Node” tab
next to the Inspector to see the list of signals the player can emit:
Notice our custom “hit” signal is there as well! Since our enemies are
going to be
RigidBody2D nodes, we want the
body_entered( Object body ) signal - that will be emitted when a
body contacts the player. Click “Connect..” and then “Connect” again on
the “Connecting Signal” window - we don’t need to change any of those
settings. Godot will automatically create a function called
_on_Player_body_entered in your player’s script.
When connecting a signal, instead of having Godot create a function for you, you can also give the name of an existing function that you want to link the signal to.
Add this code to the function:
func _on_Player_body_entered( area ): hide() # Player disappears after being hit emit_signal("hit") monitoring = false
monitoring property of an
it won’t detect collisions. By turning it off, we make
sure we don’t trigger the
hit signal more than once. However,
changing the property in the midst of an
will result in an error, because the engine hasn’t finished
processing the current frame yet.
Instead, you can defer the change, which will tell the game engine to
wait until it’s safe to set monitoring to
false. Change the line to
The last piece for our player is to add a function we can call to reset the player when starting a new game.
func start(pos): position = pos show() monitoring = true
Now it’s time to make the enemies our player will have to dodge. Their behavior will not be very complex: mobs will spawn randomly at the edges of the screen and move in a straight line (in a random direction), then despawn when they go offscreen.
We will build this into a
Mob scene, which we can then instance to
create any number of independent mobs in the game.
Click Scene -> New Scene and we’ll create the Mob.
The Mob scene will use the following nodes:
In the RigidBody2D properties, set
Gravity Scale to
that the mob will not fall downward). In addition, under the
PhysicsBody2D section in the Inspector, click the
Mask property and
uncheck the first box. This will ensure that the mobs do not collide with each other.
Set up the AnimatedSprite like you did for the player.
This time, we have 3 animations: “fly”, “swim”, and “walk”. Set the
property in the Inspector to “On” and adjust the “Speed (FPS)” setting as shown below.
We’ll select one of these randomly so that the mobs will have some variety.
In Godot’s 2D space, a heading of zero degrees points to the right. However, our mob art
is drawn pointing upward. To correct for this, set the
AnimatedSprite‘s “Rotation Deg”
As in the
Player scene, add a
CapsuleShape2D for the
collision and then save the scene.
Add a script to the
Mob and add the following member variables:
extends RigidBody2D var MIN_SPEED = 150 # minimum speed range var MAX_SPEED = 250 # maximum speed range var mob_types = ["walk", "swim", "fly"]
We’ll pick a random value between
how fast each mob will move (it would be boring if they were all moving
at the same speed). We also have an array containing the names of the three
animations, which we’ll use to select a random one.
Now let’s look at the rest of the script. In
_ready() we choose a
random one of the three animation types:
func _ready(): $AnimatedSprite.animation = mob_types[randi() % mob_types.size()]
You must use
randomize() if you want
your sequence of “random” numbers to be different every time you run
the scene. We’re going to use
randomize() in our
so we won’t need it here.
randi() % n is the standard way to get
a random integer between
The last piece is to make the mobs delete themselves when they leave the
screen. Connect the
screen_exited() signal of the
node and add this code:
func _on_Visible_screen_exited(): queue_free()
That completes the Mob scene.
Now it’s time to bring it all together. Create a new scene and add a
Main. Click the “Instance” button and select your
See Instancing to learn more about instancing.
Now add the following nodes as children of
Main, and name them as
shown (values are in seconds):
- Timer (named
MobTimer) - to control how often mobs spawn
- Timer (named
ScoreTimer) - to increment the score every second
- Timer (named
StartTimer) - to give a delay before starting
- Position2D (named
StartPosition) - to indicate the player’s start position
Wait Time property of each of the
Timer nodes as
In addition, set the
One Shot property of
StartTimer to “On” and
Position of the
StartPosition node to
The Main node will be spawning new mobs, and we want them to appear at a
random location on the edge of the screen. Add a Path2D named
MobPath as a child of
Main. When you select the
you will see some new buttons appear at the top of the editor:
Select the middle one (“Add Point”) and draw the path by clicking to add the points shown. To have the points snap to the grid, make sure “Use Snap” is checked. This option can be found under the “Edit” button to the left of the Path2D buttons.
Draw the path in clockwise order, or your mobs will spawn pointing outwards instead of inwards!
Now that the path is defined, add a PathFollow2D
node as a child of
MobPath and name it
MobSpawnLocation. This node will
automatically rotate and follow the path you’ve drawn, so we can use it
to select a random position and direction along the path.
Add a script to
Main. At the top of the script we use
export (PackedScene) to allow us to choose the Mob scene we want to
extends Node export (PackedScene) var Mob var score func _ready(): randomize()
export lets you set the value of a variable in the Inspector
Click on “<null>”” and choose “Load”, then select
Next, click on the Player and connect the
hit signal to the
game_over function, which will handle what needs to happen when a
game ends. We will also have a
new_game function to set everything
up for a new game:
func new_game(): score = 0 $Player.start($StartPosition.position) $StartTimer.start() func game_over(): $ScoreTimer.stop() $MobTimer.stop()
Now connect the
timeout() signal of each of the Timer nodes.
StartTimer will start the other two timers.
increment the score by 1.
func _on_StartTimer_timeout(): $MobTimer.start() $ScoreTimer.start() func _on_ScoreTimer_timeout(): score += 1
_on_MobTimer_timeout() we will create a mob instance, pick a
random starting location along the
Path2D, and set the mob in
PathFollow2D node will automatically rotate as it
follows the path, so we will use that to select the mob’s direction as
well as its position.
Note that a new instance must be added to the scene using
func _on_MobTimer_timeout(): # choose a random location on the Path2D $"MobPath/MobSpawnLocation".set_offset(randi()) # create a Mob instance and add it to the scene var mob = Mob.instance() add_child(mob) # choose a direction and position var direction = $"MobPath/MobSpawnLocation".rotation mob.position = $"MobPath/MobSpawnLocation".position # add some randomness to the direction direction += rand_range(-PI/4, PI/4) mob.rotation = direction # choose the velocity mob.set_linear_velocity(Vector2(rand_range(mob.MIN_SPEED, mob.MAX_SPEED), 0).rotated(direction))
In functions requiring angles, GDScript uses radians,
not degrees. If you’re more comfortable working with
degrees, you’ll need to use the
rad2deg() functions to convert between the two measures.
The final piece our game needs is a UI: an interface to display things
like score, a “game over” message, and a restart button. Create a new
scene, and add a CanvasLayer node named
HUD (“HUD” stands for
“heads-up display”, meaning an informational display that appears as an
overlay, on top of the game view).
The CanvasLayer node lets us draw our UI elements on the layer above the rest of the game so that the information it displays doesn’t get covered up by any game elements like the player or the mobs.
The HUD displays the following information:
- Score, changed by
- A message, such as “Game Over” or “Get Ready!”
- A “Start” button to begin the game
Create the following children of the
- Label (named
- Label (named
- Button (named
- Timer (named
Anchors and Margins
Control nodes have a position and size,
but they also have anchors and margins. Anchors define the
origin, or the reference point for the edges of the node. Margins
update automatically when you move or resize a control node. They
represent the distance from the control node’s edges to its anchor.
See GUI tutorial for more details.
Arrange the nodes as shown below. Click the “Anchor” button to set a Control node’s anchor:
You can drag the nodes to place them manually, or for more precise placement, use the following settings:
Anchor: “Center Top”
Dodge the Creeps!
Connecting HUD to Main¶
Now that we’re done creating the
HUD scene, save it and go back to
HUD scene in
Main like you did the
Player scene, and place it at the
bottom of tree. The full tree should look like this, so make sure you didn’t miss anything:
Now we need to connect the
HUD functionality to our
This requires a few additions to the
In the Node tab, connect the HUD’s
start_game signal to the
new_game(), update the score display and show the “Get Ready”
$HUD.update_score(score) $HUD.show_message("Get Ready")
game_over() we need to call the corresponding
Finally, add this to
_on_ScoreTimer_timeout() to keep the display in
sync with the changing score:
We’ve now completed all the functionality for our game. Below are some remaining steps to add a bit more “juice” and improve the game experience. Feel free to expand the gameplay with your own ideas.
The default gray background is not very appealing, so let’s change its
color. One way to do this is to use a ColorRect node. Make it the
first node under
Main so that it will be drawn behind the other
ColorRect only has one property:
Color. Choose a color
you like and drag the size of the
ColorRect so that it covers the
You can also add a background image, if you have one, by using a
Sound and music can be the single most effective way to add appeal to the game experience. In your game assets folder, you have two sound files: “House In a Forest Loop.ogg”, for background music, and “gameover.wav” for when the player loses.
Add two AudioStreamPlayer nodes as children of
Main. Name one of
Music and the other
DeathSound. On each one, click on the
Stream property, select “Load” and choose the corresponding audio
To play the music, add
$Music.play() in the
$Music.stop() in the
$DeathSound.play() in the
game_over() function as
For one last bit of visual appeal, let’s add a trail effect to the
player’s movement. Choose your
Player scene and add a
Particles2D node named
There are a very large number of properties to choose from when configuring particles. Feel free to experiment and create different effects. For the effect in the example, use the following settings:
You also need to create a
Material by clicking on
then “New ParticlesMaterial”. The settings for that are below:
See Particles2D for more details on using particle effects.
You can find a completed version of this project here: https://github.com/kidscancode/Godot3_dodge/releases