Very neat (and borderline addicting!) tile game. Only a few rules to keep in mind, but it's surprisingly fun how things play out in game. Play is a mix of luck and strategy and it can take a while to get the hang of things! There are a few glitches (enemies disappearing after a few seconds) that make the challenge level drop off sharply around level 30 or so, but that doesn't take away from how fun the game is to learn.