Great but hard.
Wow.
The graphics are great and the game play is great. The only problem is that it's so stinking hard! I'm not exactly the best at these types of games, but I was never able to buy anything. This is because the upgrades cost so much that you can't buy them until the game starts rolling, and because the reload time takes so long, people are guaranteed to get past when you do unless you call an air strike. And even when I was one third through the game I wasn't able to buy anything becuase I had to repair my nearly dead wall every round.
So, it's a good game but, kinda hard.