I somehow missed this when it first came to light last year, but it is still quite extraordinary. Tilt a cube to move a man around in spaces that are projected onto the surface of the cube, and rely on your own spatial associations gleaned from play to navigate the rooms contained "inside" the cube... Not only is the cube-manipulated-via-screen interface for levelHead rather unusual, the concept for the game - Memory Loci - creates a somewhat unusual problem for the player to solve. It is, as its creator Julian Oliver points out, rather like a futuristic Rubik's puzzle.
Oliver explains (sort of):
It is this navigable accumulation of spatial associations in memory that is configured as the core mechanism of play in levelHead. Rather than the computer containing these relationships for the player it is the memory architecture of the human player that describes the scope of their free movement. It is a game that in order to be played relies on the imaginary and unseen architecture being of equivalent relational resolution to that of the digital architecture displayed.
More here, and there's a splendid video of it in action after the jump.
I watch videos like this and think "some people are just cleverer than me".
I found this, incidentally, via WMMNA's write up of the Homo Ludens Ludens exhibition. It contains much that is on the weird edge of design.