If you had a Java-capable browser, you could play Tim O'Lena's 3D Chess here. Keys "s"=save "l"=load "b"=back once
Tim's 3D Chess. Tim wrote me about this variant, in which pawns can also move up, down, and sideways.
Chess Variants
Chess Variants Meet Ed
These are simple illustrations rather than strong opponents.
Bug reports? -- Thank you! Keep them coming!