This is a game I have a history with. As a Kid I loved it. As a "Cynical Teen" I believed "It didn't hold up very well when I replayed it because the game isn't as good." Then I just basically decided to shut the heck up and rate it based on how fun it is now and not how it was or how it will be.
This introduced the 3D gameplay of Sonic so you can expect it to be a bit buggy. And yes. It's a bit buggy sometimes but you know it was Sega's first attempt so you can forgive them slightly. There's 6 characters and they all play differently so i'll be rating their gameplays seperately.
Sonic: He plays just like you'd think he would. He has the spin dash and the jump like in the genesis days, but in this game he got a few new powers. He can home into an enemy by jumping twice (Akin to the Flame Shield in Sonic 3) he also has the light speed dash and attack where he can dash through a set of rings and later enemies.
His stages are action packed get to the End. (also if you replay stages a second person can play as Tails like in Sonic 2/3 ^_^. It doesn't help much but it's a nice touch). Almost perfect gameplay. I'm not saying perfect as there's room to improve.
Tails: He's like Sonic except he doesn't get the Homing Attack or the Light Speed Dash/Attack, but he can fly instead and hit robots with his tails.
Tails' stages are races against Sonic (typically) and you can beat Sonic because there are shortcuts placed that Sonic can't get to. My only gripes with this are.
1. Sonic rubberbands. (meaning the farther you are ahead the faster he goes. he even teleports sometimes.)
2. They are shorter versions of Sonic's stages.
I give it an 8/10
Knuckles: Knuckles plays completley differently. He retains his glide and climb abilties but gains the ability to dig and punch,
His gameplay is spent searching for the emerald shards. There are 3 in every level and you have to find them all.
This version of treasure hunting is REALLY fun. (SA2 ruins it a bit).
I give it an 8/10
Amy: Now this is Amy's first time being playable in the main series.(and the last that I know of until Sonic Boom: Rise of Lyric
:C poor amy).
She plays differently to the other characters in that she hits enemies with her hammer and runs away from a badnik named Zero the whole time. (No I don't find this "sexist" because Amy actually fuels the plot and her being kidnapped isn't because "Shes a dainty girl" it's because she fuels the plot.)
Amy gets a small amount of stages so it doesn't drag on too long.
I give her a 7/10
He pl-... HEY GET OUT OF MY PC! "HES A ROBOT ZOMG HE DOESN'T PLAY LIKE SONIC 0/10 SUX"... anyways yes he doesn't play like any other sonic character to date but IT'S NOT BAD! It's a fun gameplay style and it's different. (I'll go over why I love gamma more in the story section) He shoots enemies to gain time because THE TIMER COUNTS DOWN AND NOT UP! And if it gets to 0 you will die. He plays through missions.
I give him an 8/10
I don't hate Big. I think his gameplay is out of place but I don't hate him. He fishes. Thats all I have to say.
6/10 (for being out of place.)
Gameplay total: 7.5/10
Each character has a different story but I'll lump a few sets together because they are related.
Sonic/Tails: They have a story about fighting [s]Dr. Robotnik[/s] Dr. Eggman and they usually stay together.
Knuckles: He's usually on his own finding the emerald shards. Dr. Eggman managed to trick him again.
Amy/E-102 Gamma: Not gonna spoil it but they have an interaction that is great.
Big: He's usually on his own fishing and trying to find his frog Froggy but he finds a few other people along the way.
Rating: 8/10 (if Gamma's story wasn't here it would be an 7/10)
9/10. Just listen to this soundtrack on Youtube.
8/10 - Great Game I recommend it a lot.