Oh my god, are you talking about the hit Sega Genesis video game "Sonic the Hedgehog 2"? Dude, I fucking love that game! The gameplay's basically the same as the first game, but Sonic can spin dash now, and I think that's really cool! Getting all of the Chaos Emeralds can be hard, but it's actually worth it now, because you unlock Super Sonic, which is basically if you had both the Power Sneakers and Invincibility. There's this new character called Miles "Tails" Prower, but, honestly, what's his purpose in the 1 Player mode? He's just not as fast as Sonic is. But, according to the instruction manual, "Tails" is actually really smart, so that's cool. Hopefully in the next Sonic game, there's more characters.