geoDefense Swarm is an open-space, maze-based followup to the original geoDefense, a hardcore tower defense game that sparked a "love it or hate it" relationship. If you enjoyed that game, you'll love this one, and if you didn't, well, Swarm won't do anything to change your mind.
Like its predecessor, this game doesn't pull any punches. The creeps here are relentless, and they'll rush you at an incredible speed. There's very little time to build your own maze in the beginning of the level, so expect to restart a few times before you figure out a decent defensive strategy.
Crafting a defensive strategy can be very difficult at first, as the game doesn't do a very good job of explaining how to play. A few tips pop up on the first couple of levels, but none actually go so far to tell you what the differences are between towers.