Mmm...
Actually, that reminds me: why was this game rated M to begin with? It's pretty kid-friendly if you ask me. Nothing gratuitous about it in any way.
Anyway, onto the review. Not going to deny it, I enjoyed playing this game. Maybe not as open-ended as Metroid, but I can tell it's trying to be, and everything else is a faithful enough duplicate. Graphics and sounds serve their purpose, and the animation moves at a crisp pace.
If I had to critique anything, though, it would definitely be the difficulty. The money system is far too generous, and the choice it ends up giving you is in what order you'll buy everything in the store, rather than what will or will not be bought. FYI, readers? Rush the two Economics books, save up for the minigun, and you can pretty much guarantee the rest of the game will be no trouble. I got the minigun right at the beginning of chapter 2, and it allowed me to breeze past any and all enemies I encountered. Ended the game with over 3000 cash unspent, simply because there was nothing left to spend on.
Even if I hadn't bought anything, though, a lot of these enemies just don't appear in numbers or have the strength to prove any real threat. Maybe 40% of them have guns, which are fired at really slow and obvious intervals that make them easy to jump around and pelt back with complete impunity. The rest are just mindless fodder to spray at, reminiscent of weeds you fight hit with Round-Up when doing chores. In that respect, the health-maximizing items aren't even necessary most of the time.
Another suggestion for the next game is maybe having the characters have their own little quirks to their play styles? The difference between the psychotic and the gentleman is absolutely skin-deep, and that makes for a rather boring repeat of levels purely done for the achievements.
Like I said, I enjoyed this game, but it's hardly a challenge to anyone who knows what they're doing. 8/10, and I hope the next one is a little bit less forgiving.