I visited the Frozen Bubbles site ( http://www.frozen-bubble.org/downloads/ )and the information there seems pretty clear that it was designed on Linux boxes (hence the penguins).

My guess is that the two-player version is 640 x 480 in order to fit the widest number of screens (circa years ago, eh?), and the 1-player version is half that. (See pictures at http://www.frozen-bubble.org/making%20of/ .)

I don't see anything that indicates there are PocketPC or Palm versions.

-- Roger