I'm glad you like the idea! I only wish I thought of the shadow ability earlier in the jam. I realized far too late I need something to force the player to plan ahead.
I just checked the source... in my rush I forgot to set the next level for World-04.tscn... whoops ( .~.)
The controls definitely need to be changed. Originally the controls where [Z -- Jump], [X -- Place Warp], [C -- Goto Warp]... it was quite bad.