1-Old school games
Sonic the hedgehog(1991):"in this game you play as sonic to see if you can save the animals from capsules and destroy robots to free them". "You have three acts in total in each zone". "In the end you defeat robotnik/eggman and bring peace back".
Sonic the hedgehog 2(1992):"in this game you play as sonic or tails where you have to stop robotnik and save the animals from capsules again". "This marks the first appearance of tails the fox".
Sonic the hedgehog 3/sonic 3 and knuckles:"in this game tails and sonic are going to Angel island for a vacation"."Sonic decides to ski across the water using his super form super sonic". "But out of nowhere comes a echidna (knuckles) who had been tricked by robotnik and punches emeralds out and steals them". "This is the first two part game sonic's been in".
Sonic cd:"sonic is running around in palmtree panic when a pink female hedgehog(amy) come out of nowhere and chases him but just then a robot come out of nowhere and captures her". "Now it's your job to save her and restore peace".