Has anyone ever heard of a game called Konami World for the NES? It was a game released only in Japan by Konami let you play as some of Konami's most popular characters, like Simon Belmont from Castlevania and Goemon from Legend of the Mystical Ninja, who you had to rescue first. One of the characters you have to rescue to play as is Donkey Kong. I don't know how Konami got the rights to use D.K. in their game, but they did. D.K.'s level is this building filled with robots. Search the net and you'll probably be able to find a ROM of it.