Shelia the kangaroo, Sgt. Byrd the penguin, Bently the Yeti, Agent 9 the space monkey, and even Sparx the dragonfly. Each has their own home level, and then a bunch of side quests in other levels. All control very well, and it's very easy pick up. I did notice however that the difficulty level is a bit easier then Ripto.
Graphics are amazing.
The just get better with each game instalment. Everything is brightly colored and there's little glitching. They're just beautiful. Sound is just as great as in the other two games. It's done by the same artist as in the first two games, though his name escapes me at the moment.