There are six playable characters, all of whom end up caught up in Eggman's latest plan to take over the world; this time using a water based creature called Chaos (with a hugely interesting backstory). You can play through as each character (all of which play uniquely) and watch the story unfold from their different points of view (something I like very much).
First, you have Sonic. When you play as Sonic, you get what you'd expect: levels that you can get through by running very quickly. Then you have Tails. Tails’ levels are the same as Sonic's, but each time you're racing Sonic and beating him is the goal. You also have Knuckles. Knuckles, after the destruction of the Master Emerald, has big levels to explore in order to find and restore its broken shards. Amy Rose is playable too. Amy's levels are slower paced and she is always pursued by an evil robot called ZERO. Two new characters were introduced as well, and I like both of them very much. One character is Big the Cat; Big is a fairly comical character and his levels are all fishing based as he attempts to catch his missing pet Froggy. Finally, you have E-102 Gamma, one of Eggman's robots. Gamma's levels are slightly slower paced (like Amy’s) and adopt a third person shooter play style. The downside of all of this is that controls can feel a bit glitchy at times (leading to the occasional unfair death) but it's never a huge problem.
Seeing the story from these six different perspectives was a very good idea, narratively speaking. All the characters are quite likeable and there're lots of scenes of them interacting. It may be hard to believe from a light-hearted series like Sonic but it can be quite emotional at times. In fact, I'd go so far as to say that this game contains one of the saddest scenes I've ever experienced in a video game. But it can also be fun and upbeat! I get a lot of enjoyment out of Big and Eggman especially. A pair of hilarious characters there. What's also nice is that you don't just go from level to level, all of the levels can be found on a hub world and I certainly appreciated this. Some areas are nice and mysterious, making them prime for exploration, especially when you want to take things slow and not just rush to the next stage.
Another thing I really like are the Chao. This is the first game in the Sonic series to include the Chao which are a race of small baby-like creatures which you can take the time to look after between levels. The Chao are probably the cutest creatures I've come across in the world of gaming and I find caring for them in the Chao Gardens extremely fun and rewarding. You find animals in the action levels and then, when a Chao interacts with them, it can copy their abilities and you use this to make them more powerful for a series of mini-games they can take part in. I like it all because it's enjoyable and because they're completely adorable.
There is also a slightly enhanced version of the game called Sonic Adventure DX: Director's Cut, I've played both it and the original. DX is essentially the same experience but with minor graphical improvements and two significant additions; the first is the addition of twelve unlockable Game Gear Sonic games, which is very nice and the option to do some additional 'missions' after the game's story has been completed. The missions are fun, but nothing substantial. DX is probably the definitive version of the game, but you won't be missing much if you get the normal edition.
Overall, a fun, varied game (regardless of version). Rating: 8.9/10
(I do not own the copyright of the cover image.)