Sonic 1 KAwarino is a ROM hack of Sonic the Hedgehog for the Sega Genesis. The meaning of "KAwarino" isn't immediately clear without additional context, but it signifies a customized version of the original game.  Likely created by a member of the ROM hacking community, the modification probably alters levels, adds new challenges or changes game mechanics. The base game is the original Sonic the Hedgehog from Sega's 1991 release. The ROM hack's creator is likely an independent developer not affiliated with Sega.

Sonic 1 KAwarino

Sonic 1 Hyper Edition