So, I took a dive into the Nemesis compressed graphics/objects in the stage files, and came across some stuff. Collision Chaos This is a teleporter. It can be found in the 510 prototype, albeit with broken mappings. 3 of these will circle around, and when Sonic enters one, he gets teleported to another one within the circle. Tidal Tempest First, some unused platforms. Interestingly, despite the fact it doesn't seem to fit, the one on the left came from the past. The others come from the future. This is some kind of electric beam? The code for it can be found in the 510 and v0.51 prototypes. Only the v0.51 prototype has working collision detection, where touching it makes it stop. The code was removed by the 712 prototype. I wonder if these unused sprites are related... they are also found in Tidal Tempest's sprite data... Stardust Speedway So, as you may know, in earlier prototypes, Stardust Speedway didn't have searchlights. They instead used horizontal interrupts to move a lit up section up and down. These sprites were gonna be placed at the edges of the lit up section. As is, it would've looked something like: This is a duplicate set of those mesh tiles that would've been placed as objects. Metallic Madness This is a trap door. This was actually used in later prototypes, but got scrapped in the final.