The polyphonic stuff will be revealed in the forthcoming release of TETRIS for the Odyssey Called "Puzzle Piece Panik!" written by the author and great innovator of O2 software Ted Szczypiorski. with Mr Roboto pushing the O2/Videopac console to techniques that the programmers of the time did not even consider Ted has developed a way of producing polyphonic sound.
The early O2 packs contained only 2k roms, and made use of the o2s own built in character sets sucha as the mushroom/tree, humanoid, circle, that combined with them all being written by the same chap does lend the 2600 some credit.
but these restrictions were soon realised, and the rompacks quickly went up to 4k to include customised graphics.
the system, did not benefit from the 3rd party contributions to its library in the same way the 2600 did, had it have done, I think we would be able to come back and argue the merits from a higher ground. since we only have a library of at most 100 games to choose from as opposed to what (I'll let you atari experts answer that)..a couple of thousand ???
however, I can assure you that the Videopacs hayday is far from done... a global colaberation of the biggest names in the O2/Videopac world is underway, a new approach to extracting the most from this system will show exactly what this baby is caperble of.
watch the videopac/Odyssey 2 it is going to blow you away very soon.