The limited lifespan of the towers is the single most infuriating mechanic I've ever seen in a tower defense game, especially since it's completely unexplained. There's no documentation, no warning, nothing--your towers just explode, and you have to figure out if they're being damaged by attackers, or if they're just using up their ammo. Without that mechanic, this game would rate at least 4 stars from me, but as it sits I won't play it.
Great concept, beautiful art, and interesting plot, but this is THE most frustrating game I've played in a very very long time. The grid is too small for single-color combinations alone to be effective, tiles are effectively wasted on low-health targets, targeting sucks, and the combination of armors makes the fights far too long, but not any more challenging.
 "Brave Knights"){kind=icon}
 "Caribbean Admiral"){kind=icon}
 "Immortal Souls: Dark Crusade"){kind=icon}
 "Pyro II"){kind=icon}
 "Cosmico"){kind=icon}