I primarily had Genesis/Mega Drive and 32X in mind. In fact, why don't I put it that way: I'll commit to beating six unbeaten cartridge games in 2021.
Anything I do on Sega CD is an extra; that's less of a priority to me since we're much further from completion, though I still might get in a game like Stellar-Fire (if I can endure the aggravation of higher difficulties...).
However if I beat one of the 32X CD games, I suppose I'll count that, since it pushes towards the goal of 32X completion. Anyway I hope to exceed six!