added lots of comments to the player script

scripts/Player.gd

@@ -1,27 +1,42 @@
 extends KinematicBody2D
 
+# export allows us to change the value of this variable from
+#  the inspector in the editor!
 export var Speed = 5
 
 
+# this is where we do node initialization stuff
 func _ready():
 	pass
 
+# this is where we perform actions every frame (delta is how long
+#  it's been since the last frame)
 func _process(delta):
+	# if we set up velocity to be 0 then we stop as soon as the player
+	#  stops giving input
 	var velocity = Vector2()
 	
+	# an action is defined in Project->Project Settings->Input Map
+	# it allows us to set up multiple keys to strings so we don't 
+	#  have to poll for specific keys every frame
+	
+	# going left and right
 	if Input.is_action_pressed('ui_left'):
 		velocity.x -= Speed
 	elif Input.is_action_pressed('ui_right'):
 		velocity.x += Speed
 	
+	# going up and down
 	if Input.is_action_pressed('ui_up'):
 		velocity.y -= Speed
 	elif Input.is_action_pressed('ui_down'):
 		velocity.y += Speed
 	
+	# if the player is holding shift, give us a speedboost
 	if Input.is_key_pressed(KEY_SHIFT):
 		velocity *= 2
 	
+	# and finally, we move and collide!
 	move_and_slide(velocity)
 	
 	pass