Hey Las,
I'm working on a Castlevania-esque engine as well (but I'm not nearly as far along as most everyone else is), but I've dabbled significantly in 3D stuff. If you need help trying to figure out some primitives, I'd be happy to help. Not sure if you're using a third-party engine or are building it from scratch, but I'd be glad to help guide/steer you in the right direction -- just PM me.
Aside from that, it looks really awesome. Even without 3D, you have something extremely special in your hands.