This mod is just pure freaking awesomeness. I honestly thought I was satisfied with Sonic Robo Blast 2 with 3D models on when it came to getting my 3D classic Sonic fix, especially with how appealingly chunky the 3D models for SRB2, but then I stumble across this mod and tho whole community around coop deluxe and I'm left even more delighted. Classic Sonic controls like a dream here and I love how he feels like SA2 Sonic gameplay-wise, but tweaked to appropriately fit Mario 64's physics engine and the like.
I honestly could be completely content if the mod's development stopped here with Amy and Sonic getting the Badnik bounce, but like what others said, I also certainly wouldn't be against seeing more of Sonic's friends get translated into Mario 64's world, as well as the prospect of getting Super Sonic if such a thing is possible.