I picked this up as a blind buy, hoping to find a deep and powerful FPS shooter, something along the lines of Half-Life meets Robotech. What I got was a manic, if a bit cheap, run-of-the-mill FPS.
PRO: The weapons are plentiful, the combat switches from frantic shoot-em-all gameplay in the mechs to duck-and-cover while on foot, which is a nice change of pace. Some of the later puzzles start to get challenging, and there's no keycard crap to put up with. The voiceovers work quite well, and very little of it sounds forced.
CON: The story starts off good, but ends up becoming a confusing mess later on. The weapon drops are so plentiful you almost never have to worry about running out of ammo and being forced to go to melee mode. The enemy A.I. can turn from brain dead to genius at the drop of a hat, which makes the difficulty curve akin to a Six Flags rollercoaster. There's not much atmosphere, and the lack of a map can make things confusing in the later levels. The vehicle mode in your mech is near-useless. And the ending is a letdown.
FINAL SAY: If you're a fan of FPS games, mechs, and wants something new to sink a couple of hours into, this is the game to get. If you're new to the FPS scene, then it's best to start with something different.