Karryn's Prison - all the sex is done through the combat, there's a management/construction element, and the corruption is player/gameplay-driven.
Corrupted Saviors - hardcore text-only strategy-RPG where you physically, mentally and emotionally break magical girls through lots of rape, humiliation and beatings in combat. Not your normal "raped until she likes it" progression either, this gets indepth with a bunch of different personalities and corruption arcs.
Star Knightess Aura - You switch between two characters, one trying to surreptitiously corrupt the other. Very good slow corruption, much better than the average JRPG.
BMO TV - Gameshow contestants try to transform each other into brainless bimbos.
iNSight of you - Only game I know mostly focused on orgasm-denial, and it's generally awesome all-around if you like maledom.
Hero Party Must Fall - MC infiltrates an adventuring party to corrupt and steal the "hero's" companions.
Cyberslayers - Pretty over-the-top cyberpunk female-MC mind-control corruption game with a heavy emphasis on ugly bastards and non-con.
Ruin Me - rare example of a trainer where the trainee
wants to be corrupted and degraded. Also a sex-positive genderqueer Lovecraftian setting.