You can do a bit of perving on the main girls right now. Watching them change, getting them to wear swimsuits, and combining that with X-ray. Daphne has a mini-game that ends up in her wearing lingerie for you. Hermione has a slide puzzle minigame that results in her making her clothing a bit more risqué. Susan will put on a skimpy apron and you'll get a glimpse of nipple if you win her minigame, but she's fairly behind on content comparitively. Luna will show you her tits and wet panties, progressively, in her dream scenes.
There's a rape scene with McGonagall that nobody really counts and a blowjob scene with Ginny. The reason it was with Ginny instead of the main girls is because the main characters of a corruption game generally need a bit of easing into a sex scene and Joe seems to want to preserve a build up even while he adds the lewd content we want.
Right now there isn't a huge amount of content. If you're new it's probably better to wait a while. I'm hopeful for the games future currently, but it's not something I'd recommend to someone unfamiliar with it because game development isn't pulled out of thin air.
If you're familiar with it and particularly interested then you can start in chapter five with Joes stats save and skip most of the painful slog
Out of all that, susans apron, lunas dreams, the swimsuits (without x-ray) and McGonagall's rape where all that was in the game before Joe took over. I'd say that's pretty decent progress considering he's got a lot of work to unravel.