Just beat the iOS version of Sonic CD today, feels good. Decided to grind out the time attack. Metallic Madness 2 was pissing me off, but I made it through with a time of 2:14.23, currently I'm at the top of the leaderboard for time.
Granted the game just came out, but DAMN. It feels good. (And its been beaten by some guy who somehow beat the level in 30 Seconds. Is that even possible?)
I love the amount of effort that went into this, the JP Soundtrack uses the unused Loop Points from the 510 Beta to loop most of its songs. The US version either has brand new loops or extended loops using the Sonic Boom versions. They retained the Lightning effect in Stardust Speedway Bad Future from the JP version, along with the music changing to Bad Future when you race Metal Sonic. Everything is just [tornado fang]ing great. Sega should seriously consider using this engine to remake some of the other 2D Games in the series.