Ah, so you could squash or stretch the images? I think that would be in-scope for this, and pretty easy. I've also been thinking about adding a separate command for flipping so you can face the same sprite left and right (and up/down? hmm) and also get a fun card-flipping effect for free (which I discovered by accident when doing the code for Bez's Charlie HasBeen). And I don't think you can walk a sprite off an edge to make it disappear?
So a couple potential expansions, but I've been holding off until I have time to sit down and have a good think about how far I want to go with features. Glad you had fun with it!