Rocks'n'Diamonds

I want to change the player to a yamyam. and the same with the movement. when i press left the player will move left til hitting a wall. And when moving the player cant move another direction. how do i make this?

use the element properties for the player to change the graphic, use a custom element like in this level: http://www.zomis.net/rnd/download.php?id=396 to control the movement

ta