嗨，这里新人加一。
有没有人跟着官网教程走过？
我之前完全没有编程基础，现在刚入手godot，跟着官网教程走，输入官网代码之后，player根本不动我想知道是哪里出了问题，代码附在下面，请大家指点迷津，谢谢。
extends Area2D
export var speed = 400 # How fast the player will move (pixels/sec).
var screen_size # Size of the game window.
func _ready():
screen_size = get_viewport_rect().size
func _process(delta):
var velocity = Vector2.ZERO # The player's movement vector.
if Input.is_action_pressed("move_right"):
velocity.x += 1
if Input.is_action_pressed("move_left"):
velocity.x -= 1
if Input.is_action_pressed("move_down"):
velocity.y += 1
if Input.is_action_pressed("move_up"):
velocity.y -= 1
if velocity.length() > 0:
velocity = velocity.normalized() * speed
$AnimatedSprite.play()
else:
$AnimatedSprite.stop()
# pass