Zombie Invasion is a game for the iPhone and iPod Touch that lets you blast away zombies with several different guns. The object of the game is to just survive and earn a high enough score to lock your name down on the leaderboards.

You don't move in this game at all. What you do is tap on the incoming zombies as they rush your unfortified position that you stay at night after night in an attempt to survive. You've got your trusty pistol, a grenade or two, and an assortment of other guns that you'll find along the way to help keep this game interesting.

When zombies start attacking, you'll have to tap in their direction to shoot them. Some require multiple shots depending on which gun you're wielding, but you'll eventually be able to get them down. You've got to keep an eye on your ammo supply for your secondary weapon and grenades as only the pistol has unlimited. This definitely adds to the challenge of the game, making it difficult to get a competitive high score.

Zombie Invasion is a really fun game, but it lacks substance. You're simply standing there, night after night, shooting zombies in an attempt to just live a little bit longer. While the character models look cool and all, you're basically just tapping away on the screen as you wonder why no zombies have attacked you from behind, considering your back isn't against a wall or anything useful.