Don't buy it! If you played AVP2 before and you liked it, this one is just plain bad...
AVP1 was developed by Rebellion while AVP2 by Monolith (Fear, Fear2 etc.)
Among other things about AVP3:-
1> Terrible aiming system...feels weird
2> Predator is dumb without all his weapons (spear gun etc)
3> Melee is terrible
4> Play as Marine = doom (crazy aliens attacking non-stop)
IMHO, this AVP version is a lame effort....