stop telling all the answers ... spoils the fun!
Quadraxas, I think Blink meant that he couldn't get out because he got stuck...

I played to the end of the Demo. it took me some time to figure out how to equip the key, I think you should definately write that somewhere.

The graphics aren't perfect I think, but I didn't care at all when i played it, becauuse I was so busy with the awesome gameplay

bugs/glitches I found:
-the paper roll that's in one of the cells is so close to the floor that it has zsorting errors (I think that's the name) there (the floor comes through the aper) I've seen that error elsewhere as well. (don't remember where)
-I think it was the video player: somehow the game crashed when i loaded and tried to play on, as soon as the next cutscene came. So I tried starting the new game (since that way the player loaded without trouble) and then loaded the old on again: it worked (probably cause the player was loaded already).
-after loading the second time I could still see the hands that were tied together (from starting a new game) as well as the hands with the lantern (from the current game).

It's awesome how you explain the game at the beginning. just by having a voice somewhere from another cell that tells you what to do. great!
maybe you should also have it as written text somewhere, just in case someone starts the game without speakers on.

How far are you with the real story? I'd love to see how it goes on...
Good gameplay, great realization of the story...!
Micha