Great concept and clever ending. The art and crt effect were nice as well. Though, some more sfx's would be great; like moving, doors opening, robots entering/exiting range.
I found most of the puzzle to be quite difficult, but I somehow manage to beat it. I think most of the puzzle mechanics could have been introduced better to make it less difficult. Like the blocking of doors for example. Why not have a level with a d'elian stuck in a doorway to show that this is possible, instead of throwing players into the deep end. There even is a level doing this after the mechanic was already needed to solve a puzzle.
A quarter in I accidentally reloaded the page, only to discover that there was no progress saving. On replaying the older levels they were a lot easier, because I knew what I was doing. Even though I had forgotten some of the solutions.