I love roguelikes, I love bondage, and this is a great combination of the two. Great variety of outfits, restraints, enemies, and attack forms. 

This game is probably the most challenging 18+ game I've played, and the gameplay difficulty complements the theming really well. I don't think I've ever made it past the second boss, but thankfully there's lots of ways to explore late-game content without having to truly master the game.