Hey Rex, hope you're well this year.
I recall the Bimini Run work - thought we did a good job splitting out the logic into C++ with some very nice object oriented classes for managing the world and objects (Rex's inspiration), combined with just the right amount of assembly code for loading graphics. We had a very good compression manager for the 16 color objects.
The 3d stuff, I give thanks to my late college physics professor Sheridan Simon, for his math estimations. Combined with some table-lookup routines and a good arc-tangent routine that I think got by with one divide and one multiply, which was used for most of the 3d object display calculations; and with Sam K's willingness to render untold numbers of sprite image sizes and rotations, we managed a pretty nifty 15 FPS 3D world pretty early in the evolution of the Sega Genesis.
It was really fun scrambling together the support libraries for the Genesis, and too bad we didn't have the chance to follow through with NuVision's plans largely because of the credit crunch of '90.