Some suggestions, don't know if these ones have been brought up already,
Juicy Futa - Gold tier. Seems promising.
Warlock and Boobs - This one is an interesting case. While there are only two other futa characters I think. The main character can become a futa himself. The downside is it doesn't change the narrative much aside from unlocking male romance options. People treat you like the same guy, as he/him and everything. So the futa MC feels more like a cosmetic than a fully authentic one. But the CGs reflects the change at least.
Scarlett Fever - Demo. Looks promising. But I'm in doubt if the dev will actually continue this.
Naked Ambition - Low bronze tier. The game itself is pretty unique though.
Faefire-Fantasy,
A Clever Name and
Lust Awakenes - Low bronze tier games. But male MC so...
Futa Paradise - Gold tier I think?
Lilith-in-Nightmare - Complete and made by the same developers as the
succubus tamer. The translation might be slightly messy.
Meralin and Princess Kinara - Completed and really short. But it's still pretty good.
Kinokogari - Side-Scroller game with a futa MC, this might be one of the better ones. Still lacking in content though.
Isekai Lust - It's based on Ishuzoku Reviewers anime. nuff said.
Suburban-Demon-Mother Demo - Gold tier but is a pretty short demo.
Honey Select 2 libido - Game size is waaay too big.
Village Of Centaurs - Game with futa Centaurs. There are two versions - One with a female MC and the other with a male one.
Tamer - Easy gold tier. Has a neat character creator. It's still in early versions.
The Coceter Chronicles - Silver/Gold tier. It's abandoned now but it's highly praised for its futa content so I think it deserves a spot here somewhere.
Heroine Rescue Team
Eileen ~Counterattack of the Futanari Demon Lord