Play as knuckles,now on the first level go where sonic usually goes and not where knuckles does (no climbing walls unless you have to) just play as if you were controlling sonic except you dont get blow up with air when you push the switch
Now,on the end of level boss instead of being the robot he will be robotnick! This also works on level 2
Go to the showers in Casinopolis then charge up your spin dash,then stand in the shower
Face the wall then let go and maybe,there is very little chance but you get stuck in the wall and cant move and also you cant see tails anywhere!
I tried it it does work but it takes ages to do