Yay, Sonic CD!
What a coincidence: I just re-re-...-re-played through the game not a week ago! I just love the overall feel of it...
I love the levels, I love how well all the different environments are conveyed, I love seeing all the changes - from subtle to drastic - each level undergoes as you warp, I love the pointless little secrets and dead-ends hidden everywhere, I love how all the enemies in the bad future are old and broken, I love how the sky flashes in the Wacky Workbench's past, I love pressing a button while warping to the past so that the warp sound mixes so beautifully with the past music, I love the otherworldly feel of all of the special stages, I love the fiendish trickery involved in hunting down the "hamburgers"...
Man, I love this game. It's a shame it never really got the respect it deserved. I guess its being on a failed system will do that.