I don't think the ending of this game should be all that definitive. To me, this game is about the journey, not the destination.
The guy's just in college, helping out his friends and fucking girls. Sure, at that age there's some heartbreak and shit, but really those are the carefree, fun years.
All you romantic motherfuckers want him to have "endings" with these girls. He's too fucking young. Let him sow some oats, graduate, get a job, get serious and then find the woman he wants.
Settling down when you're so young...
Here's my ideal ending (maybe not the plot twist though).