Despite its few faults, this has always been one of my favourite games since I was a little kid circa the early 2000s. I'm going to be reviewing each of the six stories separately. This will be for the most part spoiler-free, the most I'll do is give a general idea of each storyline. I also won't be going into the general "B" or "A" levels, or missions.

Sonic the Hedgehog
Sonic's story is essentially the most predictable; Robotnik's up to no good and is seemingly in control of a strange monster called Chaos so Sonic needs to collect the seven Chaos Emeralds to stop Chaos. He and his buddy Tails make a couple attempts to track Eggman's airship, and a bit of a runaround ensues. (no pun intended.)
This is definitely the storyline with the most challenge. The levels progressively get longer and more difficult, more noticably in Sonic's story than anyone else's. A major issue I've always had with Sonic in the DX port is that in certain parts of levels, (for example the floating platforms in the second segment of Twinkle Park) moving while jumping is hard to control and feels oddly "floaty". I don't remember if this was present in the Dreamcast version. Other than some other minor physics issues and the nauseating Sky Deck level, Sonic's levels are definitely fun and challenging and there's a lot of opportunities for exploration.

Miles "Tails" Prower
Tails' story is a bit more sweet and simplistic than Sonic's. Tails has always been the one to follow Sonic around, but eventually has to try to learn how to handle situations on his own.
As a little kid I always enjoyed being able to skip parts of levels, so undoubtedly I learned how to skip huge chunks of Tails' levels with ease. His style of flight is probably my favourite flight mechanic out of most games I've played, though it can be more glitchy after you obtain the Jet Anklet. After you learn how to manipulate his style of flight, you can even go through all of his Windy Valley level in one jump.
Something I always found interesting about Tails' storyline is if you listen to the English voice acting, Robotnik sounds a lot more menacing and scary than he did in Sonic's storyline.

Knuckles the Echidna
As the guardian of the Master Emerald, Knuckles lives alone on the floating Angel Island. One night the Emerald shatters and the island crashes into the ocean, so it's Knuckles' job to hunt down the shattered fragments.
Again, more glitches and physics issues to be expected, but the core of the game is pretty old and the DX port is a pretty bad port. But aside from that, Knuckles is probably the most fun gameplay-wise, and he's the easiest to collect tiny animals with for the Chao Garden. His Sky Deck level is still nauseating, though.
There's this one section of Red Mountain where if you stand under a certain rock platform and change the camera to the first-person view, you can see inside of Knuckles' empty head. It's pretty creepy. This trick works with Sonic, too.

Amy Rose
Her story is quite similar to Tails' in terms of trying to become independent. However, in her storyline she's also taking care of a small bird that's being chased down by one of Robotnik's robots.
This storyline is incredibly short, and I honestly feel like it was thrown together quickly to appeal to the young female gamers of the late 1990s. However, Amy's and E-102's storylines do compliment each other very well. The three levels are quite easy, and so is the single boss fight. There's really not a lot to see or do as Amy, but using her hammer flip-jump is extremely addictive.

Big the Cat
Big is a simple cat. He lives in a hut by the river with his frog friend and they fish together. One day, the frog gets posessed by a part of Chaos and Big sets out to get his buddy back.
This is the storyline everyone commonly hates on, but I personally find it even easier than Amy's. The fishing mechanic is really simple, especially since the frog is in the same place in every level, every time you play the level. Despite this, there's actually a lot of optional exploring you can do as Big. There's optional secret areas in Emerald Coast, Ice Cap, and Hot Shelter you can only get to as him. Large character models + '90s physics = no bueno, but luckily you don't have to go through a lot of tight spots as him.
He walks pretty slow but he climbs ladders REALLY fast, which I think is a cute touch considering he's a cat.

E-102 "Gamma"
A robot created by Dr. Robotnik, he's one in the line of the good doctor's new E-100 series robots. He proves that he is the smartest and strongest in the line, but his faulty power source eventually allows him to break out of his programming and rebel against Robotnik.
Tails was my favourite character when I was a little kid, but as I got older I really grew to appreciate E-102. Because he's such an overpowered character, he's essentially given a boss to fight after every level, but it's easy to speed through his levels after playing the game a few times. He does also have the same physics issues that Big has since he's a larger character, but it's a lot more noticable as E-102 because he has to traverse a couple of tight spots, such as the room his story starts in.
I'm a fan of both the original Japanese voice acting and the English dub of the game, but I absolutely adore E-102's English voice. I always thought he sounded so sweet.

Overall
This is a crappy port of a nearly 20 year old game, so physics issues and glitches are a given. However, the majority of glitches don't pop up unless you're trying to break the game on purpose. Or, if you're just really unlucky. I've played both the Dreamcast and Gamecube versions of Sonic Adventure, and neither are really as bad as this PC port. It's still playable if you get used to it, but it definitely feels like some of the original coding got "lost in translation", for lack of a better term.
The camera work in this game is definitely not that great, and can be detrimental to a lot of levels if you're not used to how they're laid out.
The music in this game is probably one of my favourite soundtracks, because there's such a variation from techno to rock to folk music. The character themes are probably one of the things that date the game the most, they all sound so much like popular music of the mid to late 1990s that it's actually kind of funny.
Graphics and animation also date the game pretty harshly. If you have Japanese audio turned on, the choreography for cutscenes isn't too bad, but with the English audio it looks and feels a lot like kung fu movie dubbing. That being said, the English dialogue and acting is cheesy, but the voice actors did a great job. I still think Deem Bristow was the best Robotnik.

All in all, while it is a dated game (and I would recommend getting the Dreamcast or at least the Gamecube version over this port), it's a really good game with a lot of variety, and there's a ton to do post-game such as side missions and raising pet Chao. If you like Sonic the Hedgehog, games from the 1990s, or games with a great soundtrack, then this game is a must-buy.

Despite its few faults, this has always been one of my favourite games since I was a little kid circa the early 2000s. I'm going to be reviewing each of the six stories separately. This will be for the most part spoiler-free, the most I'll do is give a general idea of each storyline. I also won't be going into the general "B" or "A" levels, or missions. [b]Sonic the Hedgehog[/b] Sonic's story is essentially the most predictable; Robotnik's up to no good and is seemingly in control of a strange monster called Chaos so Sonic needs to collect the seven Chaos Emeralds to stop Chaos. He and his buddy Tails make a couple attempts to track Eggman's airship, and a bit of a runaround ensues. (no pun intended.) This is definitely the storyline with the most challenge. The levels progressively get longer and more difficult, more noticably in Sonic's story than anyone else's. A major issue I've always had with Sonic in the DX port is that in certain parts of levels, (for example the floating platforms in the second segment of Twinkle Park) moving while jumping is hard to control and feels oddly "floaty". I don't remember if this was present in the Dreamcast version. Other than some other minor physics issues and the nauseating Sky Deck level, Sonic's levels are definitely fun and challenging and there's a lot of opportunities for exploration. [b]Miles "Tails" Prower[/b] Tails' story is a bit more sweet and simplistic than Sonic's. Tails has always been the one to follow Sonic around, but eventually has to try to learn how to handle situations on his own. As a little kid I always enjoyed being able to skip parts of levels, so undoubtedly I learned how to skip huge chunks of Tails' levels with ease. His style of flight is probably my favourite flight mechanic out of most games I've played, though it can be more glitchy after you obtain the Jet Anklet. After you learn how to manipulate his style of flight, you can even go through all of his Windy Valley level in one jump. Something I always found interesting about Tails' storyline is if you listen to the English voice acting, Robotnik sounds a [i]lot[/i] more menacing and scary than he did in Sonic's storyline. [b]Knuckles the Echidna[/b] As the guardian of the Master Emerald, Knuckles lives alone on the floating Angel Island. One night the Emerald shatters and the island crashes into the ocean, so it's Knuckles' job to hunt down the shattered fragments. Again, more glitches and physics issues to be expected, but the core of the game is pretty old and the DX port is a pretty bad port. But aside from that, Knuckles is probably the most fun gameplay-wise, and he's the easiest to collect tiny animals with for the Chao Garden. His Sky Deck level is still nauseating, though. There's this one section of Red Mountain where if you stand under a certain rock platform and change the camera to the first-person view, you can see inside of Knuckles' empty head. It's pretty creepy. This trick works with Sonic, too. [b]Amy Rose[/b] Her story is quite similar to Tails' in terms of trying to become independent. However, in her storyline she's also taking care of a small bird that's being chased down by one of Robotnik's robots. This storyline is incredibly short, and I honestly feel like it was thrown together quickly to appeal to the young female gamers of the late 1990s. However, Amy's and E-102's storylines do compliment each other very well. The three levels are quite easy, and so is the single boss fight. There's really not a lot to see or do as Amy, but using her hammer flip-jump is extremely addictive. [b]Big the Cat[/b] Big is a simple cat. He lives in a hut by the river with his frog friend and they fish together. One day, the frog gets posessed by a part of Chaos and Big sets out to get his buddy back. This is the storyline everyone commonly hates on, but I personally find it even easier than Amy's. The fishing mechanic is really simple, especially since the frog is in the same place in every level, every time you play the level. Despite this, there's actually a lot of optional exploring you can do as Big. There's optional secret areas in Emerald Coast, Ice Cap, and Hot Shelter you can only get to as him. Large character models + '90s physics = no bueno, but luckily you don't [i]have[/i] to go through a lot of tight spots as him. He walks pretty slow but he climbs ladders REALLY fast, which I think is a cute touch considering he's a cat. [b]E-102 "Gamma"[/b] A robot created by Dr. Robotnik, he's one in the line of the good doctor's new E-100 series robots. He proves that he is the smartest and strongest in the line, but his faulty power source eventually allows him to break out of his programming and rebel against Robotnik. Tails was my favourite character when I was a little kid, but as I got older I really grew to appreciate E-102. Because he's such an overpowered character, he's essentially given a boss to fight after every level, but it's easy to speed through his levels after playing the game a few times. He does also have the same physics issues that Big has since he's a larger character, but it's a lot more noticable as E-102 because he has to traverse a couple of tight spots, such as the room his story starts in. I'm a fan of both the original Japanese voice acting and the English dub of the game, but I absolutely adore E-102's English voice. I always thought he sounded so sweet. [b]Overall[/b] This is a crappy port of a nearly 20 year old game, so physics issues and glitches are a given. However, the majority of glitches don't pop up unless you're trying to break the game on purpose. Or, if you're just really unlucky. I've played both the Dreamcast and Gamecube versions of Sonic Adventure, and neither are really as bad as this PC port. It's still playable if you get used to it, but it definitely feels like some of the original coding got "lost in translation", for lack of a better term. The camera work in this game is definitely not that great, and can be detrimental to a lot of levels if you're not used to how they're laid out. The music in this game is probably one of my favourite soundtracks, because there's such a variation from techno to rock to folk music. The character themes are probably one of the things that date the game the most, they all sound so much like popular music of the mid to late 1990s that it's actually kind of funny. Graphics and animation also date the game pretty harshly. If you have Japanese audio turned on, the choreography for cutscenes isn't too bad, but with the English audio it looks and feels a lot like kung fu movie dubbing. That being said, the English dialogue and acting is cheesy, but the voice actors did a great job. I still think Deem Bristow was the best Robotnik. All in all, while it is a dated game (and I would recommend getting the Dreamcast or at least the Gamecube version over this port), it's a really good game with a lot of variety, and there's a ton to do post-game such as side missions and raising pet Chao. If you like Sonic the Hedgehog, games from the 1990s, or games with a great soundtrack, then this game is a must-buy.