A somewhat crazy but interesting project is the aim to recreate Mega Man 2 for the Sega Master System. Brazil developer gvx32 has put a lot of efforts into this already. All eight levels can be displayed and music is playing. Currently gvx32 works on a meta sprites to sprites function. Adjusting more music to FM. Another update might take a while.

http://www.smspower.org/forums/15620-MegaMan2DevelopmentThread