3 Eras;
2 Sonics;
1 Epic Adventure
Platforms: PS3, Xbox 360, PC, Nintendo 3DS
About this Game:
This great game was made to celebrate the 20th Anniversary of the Sonic the Hedgehog series. Each act plays each Sonic, which are Classic and Modern, in each level. This games has three eras, which are Classic/Genesis, Dreamcast, and Modern, and each era contains 3 levels (PS3, Xbox 360, and PC), while 2 levels each in Dreamcast and Modern (Nintendo 3DS). Actually, levels in PS3/Xbox 360/PC version are rather different between the Nintendo 3DS version. As for Nintendo 3DS, Special Stages appears to get a Chaos Emerald.
About TASing:
I recommend TASing between two different platforms: the Nintendo 3DS version, and the PS3/Xbox 360/PC version, because as I mentioned, levels are rather different between the two versions. And when the emulators are become accepted, I wanted to see this game TASed in two different systems.