One of the more simplistic tower defense games I have played, and I'm pretty sure it's just ported from iOS. But if you are new to the genre and want to learn, or want some light fun on your netbook, it's not bad for $5. If you are a more serious gamer, though, you'll probably be happier with offerings like Defense Grid or Defender's Quest. A couple small gripes: there is no in-game music. The only music is on the title screen. Also, it has almost no graphics options and runs only at a 4:3 aspect ratio. The framerate is capped at 30fps (via FRAPs), but it doesn't really matter for a slow 2D game like this. Overall, though, if you are looking for a cheap, simple little tower defense game to keep you busy this should fit the bill. Just don't expect to be amazed, and if you want much depth I'd give this a pass. There's a demo, too, fyi.