I haven't read through past the first page, but I'd like to at least clear something up:
First of all, this game is super fucking old.
Second, the player does not "rape" the girls in the game. The beginning stages are just tools for seeing nakey toon girls (lifting skirts and whatnot) and the girls do not react any more negatively than any OTHER Japanese girl hentai. Just the typical "oh!"s and "ah!"s that the fullest-ly consensual sex gets from them.
The later stages is just sex. There is no rape, it is not even implied (other than the name of the game, which might be more of a pun than anything). The girls don't really react negatively to anything. They're just sort of there for the player to have fun with. They will even happily go oral on the "ghost man" player, without a hint of being unhappy about it.
From what I've seen, it's just more 3D sex game. It's about as much rape as a blow-up doll is rape; it just sits there while you fuck it and has no real opinion on the matter.
Now if the game was you chasing down a girl on the street, threatening her with a knife, pushing her to the ground, and forcefully taking her, that would be completely different.
In all honesty, the mangas where the people murder the girls and fuck their rotting corpses is far more horrible than this, just for the idea.