Defense Grid is a tower defense game released on Steam a week or so ago, and since I've made a tower defense game myself and am a fan of the genre I was happy to try it out, especially because its visuals look so nice.

One particularly nice element that 3D allowed this game to do is lines of sight: positioning towers is more realistic than in other tower defense games because towers can only shoot at what they can see. If you place one tower in front of another, it will partially block how the one behind it can fire, which leads to interesting strategy considerations.

Unfortunately, there's no demo, so buying it is kind of an act of faith. If you like tower defense games in general you'll probably like this game. The only disappointment to me was how low the challenge level is: compared to other games in that genre, it feels much easier. But the high-score tables make up for that, allowing you to create your own challenges, e.g. by trying to get in the top 100 in the rankings for every level.

There actually is a fairly competent story, too. It's brief, and amounts to an ancient computer reminiscing about the taste of raspberries and his missing son, but it's nice, and its voice-acting is well done.