Myst IV: Revelation builds on what has been done in past games and marches forward to improve the experience.
Myst IV follows the footsteps of the previous titles by presenting a deep story, lots of reading material, and many many many confounding puzzles. The game strays away from it's siblings by putting out a new level of graphics, character to character interaction, and incredible new ages to explore. When I say character to character interaction I mean that you feel like you're actually there and not some invisible camera watching events happening and changing things from behind the scene. Right off you're involved with the characters in helping with some tasks here and there before things start to go wrong- which is where the game really starts.
There really isn't that much MORE to say about Myst than what can be said about the other games. It's beautiful, immersive, clever, intelligent, and greatly difficult. But the difficulty never stops me from tinkering with each puzzle trying to find answers. Myst IV: Revelation is something to cherish and place next to your Myst Trilogy.