Reasons I didn't quite like the game:
1-It didn't play smooth. Not speaking framerate, speaking gameplay. The wallwalking was confusing compared to both AvP1 and AvP2, the limited Jump wasn't always working out as you'd hope and the basic controls just had two settings: stop and full speed ahead.
2-While nice looking, it was far from optimized IMO.
3-The story was too short. Even Singularity, a more recent SP example, did one hell of a job to sell a relatively simple story. But that's Ravensoft...
4-It's looks were too confined by the AvP movies to lure younger players. Much of that is to blame on Fox I suppose...
5-It made poor use of it's full potential, Rebellion just needed another year instead of pushing it out the door this quick
6-the MP is god awfully uninspired, and reeked of 1990's gameplay elements.
7-balance? what balance?
8-truly horrendously chosen controls, a stupid meleesystem that overshot the target (hint: BattleField Bad Company 2 did it RIGHT when it comes to immersion) and came down to a fricking quick-time-event (with que's in SP, in MP, you were left to figure it out, now where's the fun in that?
9-focus attacks, WTF
10-feeling less in control than ever.
Nah, I'd take AvP2 over AvP1 any day when it comes to gameplay and story, even it's MP was better. AvP'10 just wasn't the improvement we had hoped.
There were some good and cool things, the atmosphere was just great, the synth's were some of the best designs of characters I've seen in YEARS and the SP had some nice levels. But in the end, it just feels unpolished, undershot and underachieved.