Continuity is another of those odd little experimental platformers. This one is a bit more like Hello Worlds!, in that it's generally less fiendishly hard and more experimental.
In order to get the keys and then to the door, you must shuffle around these sections. In order to move between these sections, they have to match their neighbors perfectly.
It's a little hard to describe-you really kind of have to play a bit before it makes sense (speaking as someone who had no idea what the game's description was trying to tell me before I started playing).
But it's interesting, rather fun, not too frustrating until the last five levels, and it'll make you look at things differently than most games will. I can recommend it.