During the development of Sonic the Hedgehog there were plans to include other items that were deleted from the final version, one such item were the goggles. It is speculated that these would be worn by Sonic when underwater preventing him from an untimely and rather watery grave. Animations were created showing Sonic holding his breath, as well as animations of Sonic wearing the goggles themselves. While these didn’t feature in the final release – instead we were left with the far more dangerous air bubbles in the Labyrinth Zone – the sprites were found hidden within the original ROM.
Fascinating really that one simple design choice could have changed so much.