sonic adventure seems fine at first glimpse. it's just a more sonic - thus conceptual somewhat a more edgy mario 64. it's got it's over world, the goal is still to get from point A to point B in the fastest way you can when you play as sonic, so nothing changed there really. it had more characters which seems to make it the longer and better game,  the characters were set as the their own story mode, so after you played all of sonic's levels, or since the moment you meet tails in game, i don't remember actually you can start playing as tails, then knuckles, amy, big, gamma etc

as far as i can remember tails levels were pretty alright; they were just sonic's level but with a twist. you also had to race sonic to the end or something. seems like something the older games would have done. all things considered the sonic and tails levels really were just a 3d re-imagination of the classic 2d side scroll levels, which had it's flaws but i think many 3d games had those flaws at the time because 3d was pretty new at the time. the problem is the sonic franchise kept them.

i personally never really enjoyed the knuckles levels; i mean they we're pretty cool! knuckles was a pretty cool character and the levels gave you - unlike the sonic ones- a lot of freedom to explore and discover.

except if you wanted to get a A rank, you had to hurry up and they pretty much just expected you'd knew where the emerald shards we're located. which was pretty frustrating because most of the times they were pretty far away from each other. other than that they knuckles levels - except from the fact they were a bit glitchy at times- were at least playable.

gamma's gameplay was a bit weird, but i liked it. it loved gamma as a character, and his gameplay was just so off the wall and he felt so out of place i just experienced it as fun. also his story pretty much was about killing his own siblings, and finding out he has feelings even though he is a robot. that was a blast.

i'm still not sure what the hell amy's mode was suppose to be, and i rather stab my owns eyes out than to ever play big the cat's mode again. that probably was the most boring and forced video game experience ever.

sonic adventure 2 is the better game out of the two for me because two reasons:

while it got rid of the over world system ( which to be fair, didn't add that much to SA1 anyway, but it was new and i understand they wanted to experiment with it at the time ) it also kept the aspects that were actually good about SA1. the point was they really weren't all that exciting in SA2 though. turns out i really only enjoyed the shooting mech levels as gamma, because as tails or eggman they felt bland, boring and pretty frustrating time to time. controls felt weird, and while they weren't all that different from gamma, at least gamma felt a bit more light and floaty.

the emerald hunting times two with the addition of rouge felt just a bit too much. some levels were fun, other just way too frustrating. i remember being stuck for a while on the prison island emerald stage of rouge, just because i couldn't find the damn thing. i reset the stage a couple of times just to re-locate the emerald piece and give it another shot. 

really now, the shoot and search levels just felt like errands you had to do, and as reward you'd get to play a fun sonic or shadow level again. i don't think that's good game design. but the fast levels weren't flawless either, in fact i still think the path you had to walk on was just way too less than the abyss around it. one mistake and you would fall to your death already. it looks cool, because design wise it feels like you're high above the ground but game play wise it was just frustrating. 

the other reason i prefer SA2 is... nostalgia, really. while SA1 had that too, it just isn't as strong as SA2. I mean Chaos is a pretty cool character, and it's back story was pretty neat at the time. SA1 just kept more true to the orginal games with it's angel island, chaos emerald and master emerald all taking place in a urban world.

SA2 had the angsty and aggressive shadow the hedgehog, wich was a even more cooler sonic cause he was dark and sonic was already the definition of a cool character. not only that but there was also the military, and sure why not even the president. eggman also felt a lot more dark this time around; he blew up a piece of the moon! and his plan was to fire that cannon at earth so that people would fear and obey him. i thought eggman just made silly robots.

the level design felt a lot more dark and realistic than SA1's one. military district, city's at night in terror, rain forests and the game even took place in space at a certain point. SA2 had an edgy story and you had to know it. while SA1 was more subtle with it's story and it's progres SA2 shoved it right into your face.

that being said; it still think the final battle of SA2 - how ridiculously it might have been, still remains as one of the most memorable final moments of gaming to me. the way the hero's and the villains had to team up to prevent the ark from crushing straight into the earth just felt so powerful, and it was something i never experienced before at the time. i was still young and only played a couple of games. mario didn't have to team up with bowser in the end of mario 64, in fact he still was the final boss, so there was no surprise there. but SA2's final just like such a surprise and plot twist, i was completely hooked. 

even though the final boss it's design was a complete fucking bad joke ( a gigantic fucking ugly lizard that was suppose the be the prototype of what shadow eventually became, how they went from that to shadow i don't fucking know ) it just was completely rad to battle it as not only super saiyan sonic but also super saiyan shadow! i say it that way because SA2 was indeed the first time i've experienced sonic's super form. i've heard about it, and saw some pictures of it at the time but i never expected it to see it in this game, so you can imagine how excited i was.( i didn't finish any classic sonic game at the time, and i've played SA1 after SA2 ) 

but not only that, but during the final battle a defined and extended version of the tittle screen played and it even had lyrics! as of today i still consider live & learn one of the most memorable songs in video gaming and it's probably one of my biggest guilty pleasures. it really just adds up to the feeling SA2 gave me, the feeling of '' this is it, this is the moment, this is what it was all about, it's now or never.''

sadly, SA2 was also the death of the franchise. SA2 set the tone of the darker theme the games that followed would also follow. and we all know what then happened. non the less SA2 was a big part of my youth, and to me the ''dark'' game i'd play because it appealed to me because i wanted to be edgy, but not too edgy because then i 'd had to get a xbox or ps2.