So Super Mario Bros. Special is no longer lost by any means, and it was remade for the NES. But what about Hudson's other Nintendo games? Some of them are very interesting, and deserve NES (or otherwise) ports as well. So, how complicated would it be to do these? Specifically, Mario Bros. Special, Punch Ball Mario Bros., and the ultra rare, romless Donkey Kong 3: Dai Gyakushuu.
Mario Bros. Special already got a remake, but it was only made by some Japanese person in Petit Computer. Which is a shame, since it looks great. It can be seen here: https://www.youtube.com/watch?v=1BEMidoLFB0