gridmovement.py

extends Sprite

var grid_size = 32 
var speed = 64                # speed in pixels per second
var direction = Vector2(1, 0) # move in positive x direction, adapt this in your code for other directions
var is_moving = false
var moved_dist                # keep track of how much we already moved

func _fixed_process(delta):
	if Input.is_action_pressed("myInputAction") and !is_moving:
		#set direction here
		is_moving = true
		moved_dist = 0.0
	if is_moving:
		if (moved_dist < grid_size):
			#still have space, move on 
			var offset = direction * speed * delta
			moved_dist += offset.length()
			set_pos(get_pos() + offset)
		else:
			#time to stop moving
			is_moving = false

func _ready():
	set_fixed_process(true)