The game lets you play as a disembodied floating gun as you swipe around to aim and press a simple button to gun down waves of faceless baddies. Reloading can be done with a button press or a quick shake of the device, and occasionally you’ll get to make use of gun mounted grenade launchers. Gameplay consists of taking on waves of increasingly hard to kill enemies, from slow to aim grunts to heavily armored machine gunners, air strike spotters, and even flying drones. You’ll keep taking these guys on until you die or run out of ammunition. Useful pickups like extra ammo, health, and even air strikes will pop up randomly from time to time, and you need only shoot them to activate them. You’ll also get random temporary bonuses as you play, such as faster reload speeds and firing rates or extra accuracy. There are five areas to play in, with 20 waves each plus a bonus hell wave.

As you play you’re rewarded with experience and money to use in the shop. The shop lets you restock on ammo as well as buy new guns, or upgrades to existing guns. Often there’s more than one option when upgrading. The grenade launcher is very powerful, for example, but the tradeoff is greatly lowered accuracy on the main gun. These are the kinds of decisions the game asks you to make, and whether you succumb to the noob-tube or not is entirely up to you. You’ll also rank-up as you play, which will result in cash bonuses and the game’s other virtual currency, Overkill Medals, or OM. OM are used to purchase exclusive guns or to greatly reduce the price of normal guns. You can even get rid of advertisements with them. OM are made available for in-app purchasing, but there are several ways to get them for free, including trading regular old in-game cash for them. This is a freemium model I can really get behind. The game is quite challenging, tempting you with OM exclusive mega guns, but it never feels impossible.

The characters and environments are made of detailed, high resolution 2D art. The sound effects and music are also well done. There are a lot of nice touches to this game, such as the gun trivia displayed at loading screens, a comprehensive tips and tricks section, and lots of stat tracking. There are in game achievements to nab, plus OpenFeint leaderboards to climb. The game is a bit repetitive and difficult, and playing for free will likely mean grinding out lower level waves for extra cash, but if you play this game in short bursts, it’s pretty glorious. Give this free game a download and see what you think.