Both Quake 2 and Quake 3 were much, much better.
GAMEPLAY
The Good - Certainly old skool in places. Interesting weaponry. Return of old monsters, and other references to quake 2 will bring smiles to fans faces. Intruiging twist in the middle of the game (although it doesnt really ammount to much).
The Bad - There isnt much skill involved in the ways you fight - your best bet would be to just jump around and bit and shoot wildly. This works in Multiplayer, but in Singleplayer its a big downside to the game. The game is quite easy, I cant have died more than 10 times during my entire play through of the game. Average length, probably took me 10 hours to complete. Mediocre AI. Dissapointing ending.
GRAPHICS
The Good - Some sharp textures. Nice models - both human, monster, and weapon alike. Shadows look awesome. Much more optimized that doom 3 ever was.
The Bad - Doom 3 engine slowly beginning to show its age. Some blurry textures. Unnessaserily dark considering how this is meant to be an action game, not a horror like Doom 3. The few lighter areas of the game dont look half as good as the dark ones (the engine is simply unable). Environments get very repititive and boring after a while. Enemys magicly dissappear after being killed.
SOUND
The Good - Sounds great, all weapons sound beefy as hell. Lovely environment sounds, very atmospheric. Great voice acting.
The Bad - None.
VALUE
Not really worth its price tag at all. Wait till its in the bargain bin guys.