Many tweaks thanks to IAmActuallyCthulhu

Also change apostrophes to double quotes and update C# projects

2d/platformer/src/Actors/Enemy.gd

@@ -36,7 +36,14 @@ func _ready():
 # - If you split the character into a state machine or more advanced pattern,
 #   you can easily move individual functions.
 func _physics_process(_delta):
-	_velocity = calculate_move_velocity(_velocity)
+	# If the enemy encounters a wall or an edge, the horizontal velocity is flipped.
+	if not floor_detector_left.is_colliding():
+		_velocity.x = speed.x
+	elif not floor_detector_right.is_colliding():
+		_velocity.x = -speed.x
+
+	if is_on_wall():
+		_velocity.x *= -1
 
 	# We only update the y value of _velocity as we want to handle the horizontal movement ourselves.
 	_velocity.y = move_and_slide(_velocity, FLOOR_NORMAL).y
@@ -49,22 +56,6 @@ func _physics_process(_delta):
 		animation_player.play(animation)
 
 
-# This function calculates a new velocity whenever you need it.
-# If the enemy encounters a wall or an edge, the horizontal velocity is flipped.
-func calculate_move_velocity(linear_velocity):
-	var velocity = linear_velocity
-
-	if not floor_detector_left.is_colliding():
-		velocity.x = speed.x
-	elif not floor_detector_right.is_colliding():
-		velocity.x = -speed.x
-
-	if is_on_wall():
-		velocity.x *= -1
-
-	return velocity
-
-
 func destroy():
 	_state = State.DEAD
 	_velocity = Vector2.ZERO

2d/platformer/src/Actors/Gun.gd

@@ -11,6 +11,7 @@ onready var sound_shoot = $Shoot
 onready var timer = $Cooldown
 
 
+# This method is only called by Player.gd.
 func shoot(direction = 1):
 	if not timer.is_stopped():
 		return false

2d/platformer/src/Actors/Player.gd

@@ -7,10 +7,10 @@ const FLOOR_DETECT_DISTANCE = 20.0
 export(String) var action_suffix = ""
 
 onready var platform_detector = $PlatformDetector
-onready var sprite = $Sprite
 onready var animation_player = $AnimationPlayer
 onready var shoot_timer = $ShootAnimation
-onready var gun = $Sprite/Gun
+onready var sprite = $Sprite
+onready var gun = sprite.get_node(@"Gun")
 
 
 func _ready():

2d/platformer/src/Objects/Coin.gd

@@ -7,7 +7,7 @@ onready var animation_player = $AnimationPlayer
 # The Coins only detects collisions with the Player thanks to its collision mask.
 # This prevents other characters such as enemies from picking up coins.
 
-# When the player collides with a coin, the coin plays its 'picked' animation.
+# When the player collides with a coin, the coin plays its "picked" animation.
 # The animation takes cares of making the coin disappear, but also deactivates its
 # collisions and frees it from memory, saving us from writing more complex code.
 # Click the AnimationPlayer node to see the animation timeline.