Beargh, This is what it ended up as...
You have to get to the end point to be awesome.
Arrow keys to move.
Touch a dimensional orb to blend the dimensions together.
Blended dimensions appear as coloured circles in the top left.
Click on one to drop it and leave that dimension.
Made in about 5 hours after restarting from a complete mess.
It is still not even close to my original vision, with gameplay elements hacked in during the final ten minutes of the competition. I originally started the competition with a different game idea which I abandoned. Details here.
Timelapse video of the competition here.
I needed to do much more planning and design before I started coding. Hopefully I will learn from this for the next competition.
I will upload a more complete version of this game soon ...