This is a fine example of how.......not to make a game.
AVP: Extinction in all respects is an RTS, but if you are expecting full scale battles, cunning tactitics and stratergy, and practical use of resource management, you're going to be very disappointed.
On the other hand, if you want bad graphics, poor gameplay, small skirmishes and uninspired level design, then this is the game for you.
AVP is bad for all the right reasons, and is a sterotypical representation of a missed opportunity. The graphics are abismal - too underpowered - and the entire game could have been done on the PS1. the maps are boring and lack detail, and the AI is absoultely shocking. Watch in total horror as you order your squad to deploy one way to find (for reasons unknown) that they have wandered off in the opposite direction (usually resulting in them being massacred).
Gameplay is very unrewarding. My biggest gripe is that enemy units seem to respawn over and over again. And again. And again. And again. It is clear that the programmers have tried to induce some kind of strategic element to the game, but the constant respawning of enemy units only severe to slowly deplete your own forces, as currency earned by defeating enemies is extremely low.
Each unit has their own strengths and weaknesses, but as the game is far too hard due to unbalanced gameplay, you'll end up just throwing the lot against a single enemy in an attempt to defeat them.
There are 7 (yes - you heard it) 7 missions per race, and you'll need the patience of a lama monk to see them all to the end.I only managed to finish the game with the marines - and get this - there was no ending and very little replay value.
AVP:Extinction fails to add something new to an already excellent franchise, and is overall a huge disappointment. It's an RTS without the RTS - it even makes the movie Alien resurrection seem good. A complete waste of time and money.