I love the idea of constrained mazes like this. Another related idea is that of "plank puzzles" (http://www.clickmazes.com/planks/ixplanks.htm http://www.clickm

I love the idea of constrained mazes like this. Another related idea is that of "plank puzzles" (http://www.clickmazes.com/planks/ixplanks.htm http://www.clickmazes.com/planks/ixplanks.htm), which constrain available moves based on which planks you currently have access to.