Crazy Tanks for the iPhone and iPod Touch Review
If you remember the classic "Combat" game that shipped with millions of Atari 2600's, then you'll already know the basic idea behind Crazy Tanks. You pilot a tank, and have to shoot enemy tanks and gun positions. Tapping anywhere on the screen allows you to fire, while the radar in the bottom right corner shows the relative positions of enemies, as well as health bonuses, multi-shot upgrades, etc.
Unfortunately, you never see much of that battleground at any given time, and the lack of visibility makes the game more frustrating than it would be otherwise. There are worse ways to spend 99 cents in the app store, and with just a few tweaks, this could be a top game in my book. Don't take my word for it, try it for yourself.