It’s a simple tower defense in the same vein as Fieldrunners and Robo Defense, with wide open maps and a base entrance to guard. There are four towers made available to you: a machine gun, rocket launcher, freeze ray, and tesla coil of death. There are only three maps to play on, and you have to unlock the other two through lots of gameplay. Initially, you only have one map, classic mode, and ten difficulty levels. Eventually you’ll unlock extended and endless modes and a plethora of difficulty levels. Unfortunately, the initial grind to unlock these modes is way too slow, easy, and boring. There is actually a good deal of content in this game, but it takes quite a while to excavate it.

Every time you complete a game, you are rewarded with points. These points can be used to upgrade all of your turrets in various ways, from damage enhancements to faster firing rates. There are plenty of achievements to unlock in this game while you’re at it. The game has a surprising amount of depth for such a simple indie title.

The graphics are pretty basic and don’t stand out, but they get the job done. This game is severely lacking in sound effects, and there is no music to speak of. You’ll think your phone is muted at first, but the main menu really is just silent, with no sounds to accompany button presses. This is a pretty solid game overall, and it’s totally free. There are plenty of paid tower defense games that are much more polished and balanced, but this game is a great free alternative to those.