Room for improvement
There's potential. There are a few problems with it, though.
First off, the aim system is quite frankly crap. If you could develop it a bit differently it could make for a unique experience, but for now it's just annoying. Most games have move and aim independent of each other.
Then there's the problem of repetitiveness. It's just a little too boring. There needs to be variety. Like enemies that fire back, for instance. Different levels or missions, maybe a boss now and then.
And I'd grab some music of the NG audio portal too. ;)
Good luck with your project.