Altogether, to hard...
I think any one could agree with me... It'd too hard, and not only that but everyone comes around the corners in a couple different ways. Reloading takes too long. In any further installments, please fix the difficulty level. It also needs something like a... well... what do you call it- checkpoint! It's too long to go without one, and I'm frustrated continually about that problem.
The 3D effect is very nice, I'll give you that. Color I didn't mind at all. Once the enemies start shooting, they never stop, and a difficulty level could help... very much...