For me, one of the major shortfalls of Myst and Riven was the locked-in POV afforded by the slideshow point-and-click interface. It allowed for stunning pre-rendered visuals, but the current state of computer graphics now allows for that level of fidelity to be rendered in realtime.
This game is essentially Myst art assets imported into an FPS game engine. You can now look around in all directions, which makes solving several of the puzzles far less aggravating. No more getting lost in the treetops of Channelwood because you can't tell how far left or right you just turned and have no visual landmark to orient yourself.
It's a very natural interface for this type of game. Some feel that it lacks some of the original magic, but for me this is the definitive version of this game. I only hope that some day Riven gets the same treatment.