No eroge novels (aka 'erotic visual novels') in this list: there are so many of them that we have made a page just for them.We also have a page for Adult interactive Fiction for smut made by non-Japanese writers.You are a new principle at a failing school, and make it your personal mission to corrupt the students, PTA, and entire city.
There are multiple dungeon themes and over 10 big dungeons to beat.
If you choose not to use your potions, you can choose to "life steal" the weak downed enemies, not to mention finish off the bosses.
The game is in full English, and has been updated multiple times.
Awesome graphic and voices for a simple "choose the scene" game where this young woman (who is over 18) does things with a guy she calls her "brother" but they aren't actually related because incest is wrong, Mmmmkay.
The demo goes until the first boss and gives a good idea of the game.