Spacecorps is good. It also looked kinda silly to me, but the game grows on you. Give it a try.
I know that Teaching Feeling don't have you transforming people, but it's one of the most wholesome games that I have ever played.
I'm going to fire on all cylinders here and say whatever comes to mind.
Sisterly Love, Lab Rats (Lab Rats 1 for god sake), WVM, Ecchi Sensei, Incubus City, Mythic's Manor, Harem Hotel, SuperPowered, Lilith's Throne (this one, Trials in Tainted Space and Corruption of the Champions have transformation in whatever the hell you want), Ayura Crisis (beat'em up with glorious sprite animations, and better mechanics than a lot of brawlers out there), Glassix, Holiday Island, Imperium (either the original or the fan made. Focus on YOU transforming people), Invasive Species, Take Over, Son of a Bitch (QSP mess, but one that you must play), The DeLuca Family (another one that focus more on story than on pure sex [don't know if that's your style]), TimeLoop Hunter ( a mix of CYOA, groundhog day and alien. A very interesting concept) aaaand Realms of Lust (Make a deal with a demon, become infused with LUST and everyone gets horny when they see you. Oh, every male becomes a woman because why not?).
Sorry for the lack of editing (and information on most of those games), but I can assure you that they are very good. If you need info in one of them, feel free to ask about it.
