One of my favorite games in the world was Out of this World -- the game was one of the first with good animation of a human (on a par with Prince of Persia, but somewhat less refined). Essentially, you're an experimental physicist who gets teleported into a new world by a combination of a particle accelerator and a lightning storm. You make your way around, find interesting new lifeforms, and escape near death at their hands.
All this without intelligible dialogue. A prison guard shouts at you at one point -- I think that's the extent of the dialogue in the game.
Fantastic, awesome, wonderful game. The visual cues for when to move are pretty well committed to memory, judging by the last time I played it a couple years back.
One interesting bit about the story, you have an alien helping you out through a large part of the game, though you never control him. You find yourself in a jam and he happens to come through the opposite door and blast the guy you're trying to kill.
Apparently, there was a sequel made called Heart of the Alien which resolves a debate among my circle of friends in junior high as to the fate of the main character. The sequel was only made for a decently rare platform -- the Sega CD.
I own a Sega CD as of about three months ago.
I can't wait to play it. I have tons of work to do, but this is a special favor to myself about ten years ago. Sleepless nights before vacation will make it all very, very, very worthwhile.