Ah, great idea! I'm surprised there's so few takes like this.
However, I think you should consider a few things. Right now, playing well doesn't actually reward you with anything, unless you enjoy the danger of worrying about whether or not your faceless mens will get raped by sexy monsters. The danger is usually what people get out of the 'cute girls defend against waves of monsters' stuff, trying to keep the girls safe and then liking what happens if they don't, especially if they have to sacrifice units to the monsters.
The faceless men aren't... really erotically posed or people we're excited to look at. The draw is the monsters. But we're shootin' em to stop them from getting to us, so that aspect should feel rewarding. I'd think about voice cues and static monster bodies on the board. I know you're not making a guro game here, so the sprites could be cute pained or submissive poses, or magical sexy exhaustion arrows and magic so they're sprawled out. The libidinal drive matching the gameplay drive is the key to an erotic game, and if you're having a good game time and a good time managing a big mess of a board and keeping the monsters away, then it's a solid experience. If you actually want your guys to die cause otherwise you don't get anything for your good time then it feels mismatched.
I'm also not like... a huge fan of the :>= face but that's just me. Anyway, this is a promising start and a good idea. I'm excited to see how it develops!
