Good in theory, bad in everything else.
There are 2 reasons why you probably shouldn't touch this game. First, you'll see the most disturbing creations of enemies ever thought of in a game programmer's head. Even in the first level, you'll find a giant floating brain with a human body attached, with a strange noise emanating from it. It was lovingly named walnut head. You'll also see a boss which is essentially a giant undead dragon/fish thing with giant-sized eyeballs flying at you while you shoot unheard of amounts of bullets while standing on top of an airplane.
Number 2. The difficultly continually switches from very easy to very hard. You can do quite a bit of the levels by just holding dodge in the right directions, avoiding every gunshot going towards you. On the other hand, like at the military base, it can be so frustratingly hard you'll have to put down the game. The final boss was so irritating that I couldn't even bare to continue. Trying to vainly shoot flying ghost heads bopping up and down and taking 1/5 of my health each was not what I had in mind.
The graphics are mediocre, the sound isn't interesting in the least, and the game itself can take 6 hours only to finish, assuming you even try that. Avoid this game like the plague.