A concept with potential
'Like that you decided to try and take flash gaming a step further with FPS mechanics. I must say, though, the FPS play isn't new for flash games. There's a few games in Newgrounds like that. I've seen some in the Zombie collection. Unlike the other games, however, yours features an iron sight zoom.
Some issues, though.
After night vision the primary weapon started to get buggy. It had infinite ammo when the clip size didn't show and I couldn't reload. Also, the primary shoots ghost shots when switching targets on full auto. There's also something about the zoom in. Personally, it didn't seem to make a difference since hip fire was just as fine. Just aim target at the center of the reticle.
Not too bothered with the last part being that this is a beta, but it's something you should note. You should probably add recoil, make the bullet spray in the reticle so you'll have a chance to miss and give zoom in a purpose. It'll probably be easier to take off the reticle for hipfiring, though. I was able to shoot targets through the wall, but that's no big deal since some walls can be shot through. Still, I'd look into that. Can't say much about the knifing other than it works, but nothing to test lethality, hit accuracy, or anything like that.
Over all it's not too bad for a beta game. You've got some things to fix and it's good you've made this for people to look for the issues. All you gotta do deal with those issues as best as you can and try out the fixes in the next submission. Good luck to ya.