This sounds really interesting, I would love to hear more and see some screenshots comparing the 8-bit and 16-bit graphics. Will the two modes effect gameplay?
Neat! Two comments: 1) The sound effects seemed to be the same in both modes, you really need to switch effects & music along with the graphics (if you aren't already) 2) The box is a nice touch - you should put a print & assemble version up somewhere and a link to it from within the game (or on your page) when the game's done!