So... The game is fine. But it could've been much better.
It goes like this: Normal stages are just too easy! Most guards don't have guns, and even the ones that do are fairly easy to deal with. The unarmed guards can be constantly dealt with fists by punching and going backwards. There is way too much equipment for you and none for the guards. It never really felt like a challenge when I was armed to the teeth and with a bunch of med kits.
The only true challenge is when the boss rolls around, but the boss is just too hard, at least in comparison to the average police officer, it was a surprise when, after two hits I was almost dead. and if he kills you, you get back to the start and have to deal again with a bunch of uninteresting cops, for many many floors. It gets boring..
The game is indeed fun, but it could have been much better, it has a problem in difficult, it lacks variety and it gets repetitive.
Hope my review wasn't too harsh, I hope you understand the problems I pointed out and use this to make even better games in the future!