It's an okay base that could be developed into something interesting. I don't want to repeat myself because johnnypork's review already sums up a lot of the gameplay issues.

The music is too loud, I had to turn it almost all the way down. The recoil is also too strong, but that's not even the main issue. The real problem is that when you hit an enemy, the crosshair locks, so you don't really know where you're aiming. By the time it comes back from the recoil, you're probably aiming somewhere else and have to readjust again, which isn't fun gameplay, it's just annoying.

Also, the background and enemies feel too bland. It would be nice if enemies emerged from behind columns or cars, Matrix-style, like those old on-rails shooters, or something similar, instead of just being clay dummies falling from the sky on a blank background. It would feel much more immersive.

I don't think it's a terrible idea, but right now it feels more like a tech demo. It needs A LOT of work, but it could eventually turn into a cool game.