Ok, so a good part of how this works is SPFUNC. Using that, you can make sprites move themself around. Also you have to put in CALL SPRITE in the game loop. If you look at the code, lines 13 to 20 is the game loop and line 17 says CALL SPRITE. This is the code where you update the game once per frame. Next we have a pair of functions CREATE_SHOVEL (lines 38-56), and UPDATE_SHOVEL (lines 77-92).