Admittedly I'm not really into single player games, but I checked out the Deadly Dozen Demo today and was impressed. Not by the game so much as the engine and the art. The flora/fauna effects are very well done, birds chirp, grass sways in the rainy wind and the trees are excellent. One of the best looking outdoor scenarios I've seen in a game. The animation and player textures are well done too. The weapon models are kind of average.
The coolest part is the jeep driving in the tutorial though. This engine would rock for an online fantasy game.
Anyways check it out at :
http://www.n-fusion.com