1. Scene Setup & Hierarchy

-Click the + tab at the top of the editor to create a New Scene.

-Click Other Node, search for Area2D, and select it as the root node.

-Rename the root Area2D node to enemy.

-Add a CollisionShape2D as a child of enemy.

-Add a Node2D as a child of enemy and rename it to enemy_type.

-With enemy_type selected, add four Sprite2D child nodes and name them:

2. Node Inspector Settings

enemy_type (Node2D):
- Select enemy_type.
- In the Inspector, expand Node2D ==> Transform.
- Set Scale to x: 0.46, y: 0.46.

CollisionShape2D:
- Select CollisionShape2D.
- In the Inspector, set Shape to New CircleShape2D.
- Set Radius to 22.09.

Sprite Textures: Select each sprite node under enemy_type and drag its matching asset from res://assets/enemies/ into the Texture slot:
- green_enemy= res://assets/enemies/enemy4.png
- yellow_enemy = res://assets/enemies/enemy3.png
- blue_enemy = res://assets/enemies/enemy1.png
- pink_enemy = res://assets/enemies/enemy2.png

3. Adding the Node Group

4. Adding Enemy script(res://scripts/enemy.gd)

Line-by-Line Code Breakdown

var row: int: Tracks which row grid position this enemy belongs to.
var right_edge: float = 1120.0 / var left_edge: float = 20.0: Defines boundary positions for movement limits across the screen.
var score: int: Holds the point value awarded to the player when this enemy is destroyed.
var can_take_damage: bool: Flag to control invulnerability or hit-detection states.
var sprite_applied: bool = false: Tracks whether the enemy's visual sprite has already been enabled, preventing redundant logic from repeating.
_ready(): Called once when the node enters the scene tree; executes set_animation() to initiate hover movement.
_process(delta: float): Called every frame to run set_sprite().
set_animation():
- randf_range(-3, 3): Generates a random starting Y-offset to desynchronize hover animations between multiple enemies.
- create_tween().set_loops(): Instantiates an infinitely repeating animation loop.
- tween_property(...): Smoothly animates the $enemy_type position up and down on the Y-axis to create a hovering effect.
set_sprite():
- if sprite_applied: return: Instantly exits the function if the correct sprite variant is already visible.
- enemie_sprites dictionary: Maps each sprite node (green_enemy, yellow_enemy, blue_enemy, pink_enemy) to its corresponding row index (0 through 3).
- for i in enemie_sprites loop: Iterates through the dictionary data, showing the sprite matching the enemy's assigned row and hiding all others.

Setup Space Invaders Player Shooting

Space Invaders Create Enemies Mob