Hi there, once finished with this (very close at this point) I am thinking to create some brand new levels, but the idea is to keep the same style. Talking about other classic games, many many years ago I also re-programmed in full Phoenix, it can be found and played online.
Galaga is also a good candidate for the future. My idea is re-program 4-5 classic games and for each one add a new section with new levels and/or new game modes, work in progress ;-)
Have a try at the latest build of Donkey Kong, I just added collision between hammer and barrels and a few sound effects