player = {}
player.x = 20
player.y = 20
player.sprite = 0
player.speed = 3

function move()
 player.moving = true
 player.sprite += 1
 if player.sprite > 3 then
  player.sprite = 0
 end
end

--called once per update
--at 30 fps
function _update()
  player.moving = false
  if btn(0) then
    player.x -= player.speed
    move()
  end
  if btn(1) then
    player.x += player.speed
    move()
  end
  if btn(2) then
    player.y -= player.speed
    move()
  end
  if btn(3) then
    player.y += player.speed
    move()
  end
  if not player.moving then
   player.sprite = 0
  end
end

--called once per visible frame
function _draw()
  cls()
  spr(player.sprite, player.x, player.y)
end