For button input in a game, use BUTTON(). There are multiple parameter choices for getting what button(s) are being pressed. Also, if you haven't already, check the reference on smilebasic.com
SPSET adds a Sprite (An object that moves around)
BGPUT adds a backround tile
SPOFS allows the sprite to move
SPSCALE changes the sprite size
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Get used to using variables. and loops. the start of your program should be a big list of setting up variables. It may seem like a hassle, but will make things easier to change later on.