You need to work on the drifting more. I noticed that the drift activates when moving the Left Stick rightwards. I don't know why it does this, maybe it's something to do with SRB2 itself, but I can only assume it's a bug with your mod.
It's annoying too, since it often gets in the way of me turning corners and drifting when I don't want to.
Also, could you maybe add the air drag from the unleashed/generations games as well? I don't think it's been added yet, I couldn't tell.
The only thing I really want is the ability to disable the drift independently from the physics, as it can often get in the way of some mods, and I don't think the exceptions for the Modern and Adventure Sonics really makes up for it.
It's overall really promising, and I hope to see more of it.
I'll start working on making the mod more keyboard friendly as soon as possible.