This one's a simple one, but still worth your time. It's called Sheep Impact, and the whole premise of the game is that you fly around in a hot air balloon, rescuing sheep that are inexplicably strapped to dynamite.
Sheep Impact is one of those "ascend when you touch the screen" games, so essentially, you're trying to time to descent correctly so you can pick up the sheep (done by running into them) and then ascending before you crash into anything. It's exactly what you'd expect if you played any games in this genre, so you know what you're getting.
Graphically, Sheep Impact is simple but cutesy, if I'm allowed to say that. Colors are bright and sheep look, well, like sheep. Because of the simple graphics, the game hums along nicely on my EVO 3D, but I'd imagine you'd still get great performance on lower spec'd phones.
Scoring is done via a medal system, so nabbing all the sheep nets you a gold medal. Miss one (or some), you get a silver, so on and so forth. Grabbing the coveted gold becomes more difficult as you venture into the later levels, because more and more sheep keep getting tacked on to your list to rescue.
Sheep Impact is 99 cents in the Android Market. If you're looking for a fair bit of fun and this game is your style, we've got download links after the break.