This game is awesome!! I loved it as a child. However, the port is indeed awfull, and you should not buy it. Movies are not played fullscreen, but in a weird interface, which I really dislike. Mouse controls are weird, hover on targets/pickups doesn't change cursor and no multiplayer... Give us the proper original Dosbox version, or nothing. Not this nonsense.
I am a huge Myst fan, but when this 5th game came out I was very disappointed with it. First of all, the graphics suck. It's not prerendered, but "real" 3d, what totally breaks with why Myst was so awesome: it looked always very real and convincing. Second: there are strange creatures running around in this game. It felt like a quake game or so to me, so completely non-myst. I did finish the game, but the bad taste never left. I guess if you played the other myst games you'll have to play this one too, but be warned, it sucks. This game should never have been made.