Tanks is a simple turn-based game. Each player has a tank. On your turn you select the angle to shoot and the power, and then fire. Some minor physics determine travel of the shot. Then there is collision and damage calculations. Rince and repeat until there is only one tank left standing.
I'll get Foo to post an about Foo thing here aswell. Foo has an LG p500 (Optimus One), that runs Android 2.2. Slightly better specs than the Galaxy 580 for a similar price. Galaxy 580 runs Android 2.1, so will use that as the minimum version.