I'm not done playing it yet, but so far it's amazing. I'm giving this a 10/10 for all the awesome aspects of it, such as upgrades, being able to actually use the towers, and the various missions. The single problem I've witnessed so far is that zombies can get stuck directly next to the tower, which makes it impossible to kill them due to not being able to fire that close. However, this may be just because I was using a cannon tower.