I use spanim .,"i" quite a bit. So the "I" changes the used sprite over a number of frames. in the screenshot, when you press up, i have the sprite 508, wait 4 frames, sprite 509, wait 4 frames, etc. all the way to the 0. The last number is how many times you want the animation to play. If set to 1, it will only play 508-511 once and so on. 0 makes the animation play indefinitely.