one idea i had was a match-3 puzzle game, since i already started one for NES (but haven't finished yet bc i burnt out on trying to work with the PPU, something that wouldn't be a problem in DOS & i get to use a mouse) and there aren't many (to my knowledge) DOS bejeweled clones
like i super get the importance of starting off with a beaten-path project to really hone in your skills and stuff, but also i wanted to make something that would be more interesting than "ah, that's neat" and quickly forgotten