Some (Hopefully) constructive criticism...
1) You could REALLY use a better English translator. There's actually some good foundations upon which you can build a decent story with good characterization, writing and humor. But it's hard to get past the VERY bad spelling and grammar. Not impossible, just hard.
2) Having the sex scene with the redhead should probably show some virgin blood. She talks like nobody ever even considered touching her before so it's a bit strange she doesn't bleed if you have sex with her. And yes, I know there are other ways a girl can lose her hymen besides sex. If that's what happened, maybe have her explain it so that it makes more sense.
3) The blue mutant girl....either make her tail blue too, or get rid of the tail. The brown tail on a completely blue mutant is just weird.
4) MAybe make a system that lets us create some RPG stats for the main character himself, so he can personally become a bit more of a badass.
So far I like it. Which is surprising because I usually hate things with such bad "Engrish" and despite what others have said, the Engrish here is pretty bad. But I can't help but dig it so far. Even with the rough translation I can see there's some genuine effort here at developing characters with distinct personalities, motives, and drives. Don't get me wrong it's not going to win any storytelling awards but it's noticable, engaging, and well-apprecciated.