A classic first-person dungeon crawler, but co-op and with a classless skill-based system.
Games like Ultima Underworld, Arena, Daggerfall, Descent to Undermountain, Battlespire, Arx Fatalis... those games are my jam, and they have basically died off. My favorite RPG systems also tend to be skill-based rather than class-based, and Asheron's Call (the original) had one of my favorite systems. I'm also all about co-op these days... so I want a co-op dungeon crawler with a skill-based system that looks and feels modern, like a natural evolution of those classics. And it has to be more than a hack-and-slash... it needs to have the depth and immersion of tabletop dungeon crawlers.
I've actually been working on it for a while now in UE. It's purely a hobby/passion project, so who knows if I'll ever have something to distribute... but since nobody else has been bothered to make it*, I will.
Barony is closest, but it's too deliberately old-school for my tastes... and Dark & Darker is a little too repetitive and undermined by the PvP.