Survived for 10 minutes. The start of the game is fun but it gets repetitive pretty fast. I've been standing in place most of the time and just reacted when the level up happened. I also don't like that you only get one upgrade per level, while having more towers than you could possibly upgrade. I think some sort of currency and linear upgrade path would've worked better in this case, as right now you just can't feel the tower upgrades doing any good in later levels.