3 words: Buy This Game!
This game is nearly perfect. It has everything that makes a first-person-shooter for the PSP great. It has:
-superior graphics
-awesome game mechanics (those of the Syphon Filter series)
- enemies with the ability to think creatively (your multiplayer opponents-even the worst player will surprise you from time to time)
-a wide variety of weapons with different functions
-tons of awesome customizable options
-very nice unlockables
The only things I personally would add would be the ability to run and/or roll to escape enemy fire.
But really, I think this is probably the best online-game for the PSP ever!
For ten dollars, you can't go wrong! So buy it!
Oh, yeah, and I don't know why this site calls it an expansion because it does not require you to own either of the other Syphon Filter Games. Also, I never had any real trouble getting into a game like someone complained when it first came out.