I gameshared it a couple of days ago. Singleplayer is pretty useless lol. It reminds me of the UT3 SP, more like a training. I completed 1 level at midnight before going to sleep and I finished SP the next day (SP only has 8 -short- levels). I like the guns, and the respawn technique. The maps look decent kind of boring tough. It's fun the game has bots so even when servers close you can keep playing. Also the running that goes to 3rd person and the jetpack are fun to use.
Something I dislike tough is the horrible texture glitch. Often I had when I hit the ground after flying through the air, the textures weren't loaded so they looked like PS1 textures, really blurry and ugly and it does that pretty often..
All in all for 10,- you can't go wrong, especially if you liked the demo.