They are simple ROM hacks and faked screenshots, I'm afraid. They've been around for a while.

There is only one Sonic 2 prototype that is not on my site and it is the Simon Wai one.

I do know of more Sonic 2 prototypes. For example, I know of one that is like the Nick Arcade one, but with Mystic Cave Zone and Hill Top Zone finished. But I have yet to really locate it, the track runs cold somewhere...

If I ever have anything solid on any new Sonic proto, you will hear about it, don't worry.