When Namco's Tank! Tank! Tank! served as Wii U launch game in November of 2012, it was criticized for having little more content than a mobile game. As it turns out, that wasn't an exaggeration. That game's one drawing feature, hot multiplayer tank-on-tank action, is now available For Android in much the same form thanks to Iron Force from Chillingo and Cool Fish Games.
Iron Force lacks a single-player campaign, outside of the ability to play against bots. The idea is to compete against other players in 4 vs 4 teams or in 6-player free-for-alls. There are over a dozen tanks to pick from, and while they're all understandably clunky, there are plenty of available upgrades to improve them with.
The game has already drawn fans on iOS, where it's available as a free-to-play game with plenty of in-app purchases. The Android version takes the same form. Those upgrades don't pay for themselves, after all.
The game also makes use of fuel, which replenishes over time when you're offline. Aside from that restriction, you don't have to pay anything to hop online and start blasting opponents into oblivion. If it makes the game more enjoyable, just pretend those thing you're shooting at are IAPs.