I have Pro-motion, and to be honest I don't really get on with that program, I find it clunky I guess, even though it has plenty of features and is decent for pixel art. I prefer PaintShopPro 9, I'd say it's ideal for 2D games, because it's great for pixel art while still having the features needed for everything else. Pro-motion lacks key features, like layers, it's really best for strict pixel art, where you might want a limited palette and an editor that makes it straightforward... no need to have colour sample swatches, because there's a fixed palette for that - there's probably other benefits that I haven't seen of course.
The other thing is language. AppGameKit is awesome, if you want to work with sprite sheets and tile sheets, then it's ideal. For instance, you make a sprite, tell it about the sprite sheet (sprite width and height etc), and tell it which frame to show. Sprites can be automatically animated, it has Box2D built in, and it has a very useful camera system - no need for complex scrolling code.
A copy of PSP9 and AppGameKit and the world is your lobster.
Health, Ammo, and bacon and eggs!
