"I noticed IGN gave this an extremely high review.....is it truly correct?"
Oh, yes. The game is really awesome. It's one of the Top 5 best games on the platform, without question. It's pretty lengthy for a shooter (has around 14 boss fights. At least ones that feel like boss fights anyways), especially for a portable shooter.
I personally don't like shooters that much. Haven't really enjoyed a shooter, multiplayer or single player since I first played Doom and Doom II on PC. Didn't terribly like Halo, Quake IV, CoD4, etc, but as a person who doesn't play like shooters that well, I can still say this is an amazing game.
I haven't been on multiplayer much, but when I have, it's usually been pretty busy.