Sonic 1337 is a fan-made game for the Sega Genesis, likely a ROM hack of Sonic the Hedgehog or Sonic the Hedgehog 2. The '1337' in the title is internet slang for 'leet,' often associated with hacking and skill. This likely hints at the game's altered gameplay or difficulty. The exact nature of its changes is hard to determine without playing the ROM itself.  Given the title, it's probable that the game features altered level design, possibly enhanced enemy placements, or even new gameplay mechanics not present in the original games.  It's a testament to the enduring popularity of the Sonic franchise that fans continue to create and share such modifications.  It's a product of the independent homebrew gaming community, relying on community sharing and emulation.

Sonic 1337

Sonic 1: Sonic 3 Edition