Yeah, you're right. A few glitches were patched when the GC version was ported to the old PC version. The latest PC version(XBLA/PSN/Steam) has just had a Free Camera/Auto Camera change and re-added a few enemies and objects the old PC version lacked(like the enemy at the beginning of Sonic's Final Egg). There's also a large change in collision detection, making Emerald Coast a bit harder. The ground curing to rock and an underwater section RIGHT after the 2nd-to-last Checkpoint... There's only one spot where you can go from the rock to the water on the PC versions, as you can do that transition just about everywhere at that point on GC and DC. Oh... And Casinopolis has added barriers. There's probably a few more changes neither of us mentioned, but... Let's just leave those out of this blatantly long message XD