Back in 2011, gaming business site Gamasutra published an article about a little-known fact on Donkey Kong's development history: Due to a dearth of experienced programmer at NOA, Nintendo hired another (uncredited) development team to program the game. Nintendo later broke the term of the contract with said company and were sued over reverse-engineering the arcade DK code for Donkey Kong. Jr.
This goes on to explain why the arcade version has yet to be rereleased and why the recent "Original Edition" went through the seemingly pointless process of recreating the cut arcade content with the NES assets. It's also an interesting (and less-than-flattering) factoid about one of the most important game history, so figure I might as well share it.
Nintendo hired another contractor called Iwasaki Engineering to disassemble and reverse engineer Donkey Kong so that Nintendo could add new graphics, stages, and mechanics for a sequel. This time, the nature of the agreement was clear to both sides from the start, and would turn out to be a long and fruitful partnership. As Nintendo established its internal R&D, many members of Iwasaki would join its ranks. Before long, Nintendo was developing hit games completely on its own. [...]
But for all its very original ideas, Donkey Kong Jr. was still built on code reverse engineered from the original game -- code that was already the center of a copyright dispute. In 1983, Ikegami Tsushinki filed a ¥580 million copyright infringement suit (about $8.7 million adjusted for exchange rates and inflation) over both Donkey Kong and its sequel.
The legal battle dragged on for years, long after Ikegami left the game development business. In 1990 a court ruled that Nintendo did not have the rights to Donkey Kong's code, and the two companies settled out of court for an undisclosed sum. With the case settled and Ikegami long gone from the gaming business, little is said about Miyamoto's anonymous collaborators and the role they played in one of gaming's most important titles.
This goes on to explain why the arcade version has yet to be rereleased and why the recent "Original Edition" went through the seemingly pointless process of recreating the cut arcade content with the NES assets. It's also an interesting (and less-than-flattering) factoid about one of the most important game history, so figure I might as well share it.