Play Sonic Games on Emulator Online. We have the best Sonic games online for different retro emulators including GBA, Game Boy, SNES, Nintendo and Sega. There are over 25 online Sonic games in our collection. All of the games that you see here are without download, pick any and start playing right away. If you enjoy the game, be sure to vote for it and leave a comment. Sonic games that started it all back in the day are now playable free within your browser! Start by playing some of our popular Sonic online games like Mario vs Sonic EXE, Sonic Advance 3, Sonic the Hedgehog 3 and Kirby in Sonic the Hedgehog 2.