Choose your path...
I guess it's fairly safe to say that this is a homage to the Virtua Cop shooting games. I was more a fan of the Time Crisis series myself, as being able to duck from enemy fire was more skilful than relying on firing before the enemy hit you, as well as being significantly more realistic.
I think you've done a great job with this. The graphics are cartoonish, but then again, so was Virtua Cop. It's fun, it looks good and it plays well. The sounds are really good too, I think I heard a few familiar sound effects from HL2. The only thing I would complain about is the hostage voice acting. The "Help Me!" line sounds really whiney, like it's been recorded by a kid in high school. I think that's the only area that lets it down.
Good effort though. It was a lot of fun too.