Clockwork 4x4x4A 4x4x4 with all layers of one dimension linked into one coordinated movement.
Crazy 4x4x4The first 4x4x4 with circles. It exposes the theoretical inner 2x2x2.
Crazy 4x4x4 IIThe next logical step after the Crazy 4x4x4. A very clever implementation of the Super Crazy 4x4x4
Crazy 4x4x4 IIIThe third 4x4x4 with circles on all six sides. The circles are larger as in the first two variants.
Dia-Cube 4A 4x4x4 bandaged with a known pattern of a smaller bandaged cube in one corner.
Eccentric CubeLooks like a 4x4x4 but is a 3x3x3 with three additional layers of cubies.
Framed CubeA 4x4x4 reduced to the maximum! The inner 2x2x2 is visible and has to be solved too.