Good points Atarifever. Maybe they need to get more better brains working on the sidescrollers.
On another note, it would be nice to see Castle of Illusion touched up and released for the 3DS. The game has remarkable backgrounds, which would look spectacular in 3D. They already look 3D on the Genesis anyway.
Just finished it. I only got it because it was on sale, and I had very low expectations. I don't think it's a very good game, but I didn't find it as horrible as some critics proclaim. Only the tedious sidequests (for which you have to replay levels again) really bothered me.