When examining the level files, the Rounds skip from R1 (Round 1, Palmtree Panic) to R3 (Round 3, Collision Chaos). There is no R2 to be found. Its existence is also proven by using the Stage Select menu. When switching between levels, it skips from Round 1 to Round 3, again leaving out Round 2. Additionally, one scene during the credits slideshow features Sonic running around and dodging an Antlion in what looks somewhat like a ruinous setting. In an interview, Jim Tretheway, a programmer for the Windows 95 version of the game, stated that he had the impression from original planner Junetsu Kakuta that the level was cut, because it did not meet quality standards. According to Masato Nishimura, the level was planned to be a "technical" Round that focused on exploration, like Tidal Tempest.
- In the Time Attack Level Select in the Sonic the Hedgehog CD v0.02 prototype, R2 can be seen, meaning the Round was removed between December 1992 and May 1993. However, only two Zones of Salad Plain are on the disk, so R2 is not selectable.
- "Little Planet", the theme of DA Garden in the Japanese soundtrack of Sonic the Hedgehog CD, was originally planned to be R2's present theme.