There's currently a good/revenge/harem path being made where everyone, or at least almost everyone will be fine.
There is a route that will just let him join the dark side. (hardcore naughty stuff.) It's all planned for the next two updates or so.
I think both of those routes will have good or bad endings at some point but that will be a long time away from now.
There are currently 4 secret endings that won't affect the game as of yet. Two might be seen as bad, one as funny, and one as good.