SKA, there's a lot to it but long story short, MC can do lewd things in the fantasy world that increase Corruption (that's just one of the sources of it), which one of the antagonists uses to corrupt her IRL. Definitely has a slow buildup for the IRL corruption. Most of the fantasy stuff is prostitution, drugging and hypno, while IRL is focused on cheating (well, it hasn't really started yet so it's mostly masturbation so far).
Karryn's Prison has the most indepth female-MC corruption system, driven by the gameplay in combat and jobs. DIY corruption, has a learning curve though if you want to do it your way and not just get dragged along with whatever happens.
SR is similar, but earlier and rougher.
Cyberslayers might be worth looking into as well, with a lot of choices for mind-control corruption. I don't think it's tied into a proper gameplay system yet though, it's more freeform.
BMO TV has a lot of gradual bimbofication and other TFs (latex gimp, maid, schoolgirl and more). The gameplay is questionable (being based on QTEs and RNG) but there's replay value and a lot of customizability.
Corrupted Saviors has probably the most indepth male-MC corruption system. Many options for how to break the heroines through rape and trauma in combat.