Sega had some auspacious ideas for the release of Sonic the Hedgehog 2 on the Sega Genesis, moreso than what they were able to do. See, there were some hologram labels that were intended to be used on the cartridges but for some reason those plans fell through.
These labels were created out of the love that Al Nilsen had for the Genesis and wanting to set it apart with quality releases such as Sonic 2. Due to high production costs, these labels were never put into production and only appeared, as far as I know, on the cover of one magazine from that era- Video Games & Computer Entertainment from October 1992.
Source: Retro Game Network