Myst III: Exile is rendered in 3D and is a mix of first person exploration and animations. The game is, as were the previous two Myst games, a puzzle adventure.
The antagonist in this game is Saavedro, a former student/disciple of Atrus, creator of worlds. Saavedro was left to die on a ruined world. Having gone mad, he sought revenge against Atrus by creating an intricate trap of puzzles. The player starts the game visiting Atrus, and is sucked into the trap in his stead. Wackiness ensues.
An interesting twist is that this game was not made by Cyan, the company that created the concept and the first two games. Presto Studios, with Cyan's permission, is the creator of Exile and possible subsequent Myst games. If you liked Myst, you'll probably like Exile. If you thought Myst was too slow… Exile probably won't change your mind about the series. But it is really pretty.