A tradition that dates back to the early days of arcades! Here’s a message hidden inside the code of Donkey Kong:
CONGRATULATION !
IF YOU ANALYSE
DIFFICULT THIS
PROGRAM,WE WOULD
TEACH YOU.*****
TEL.TOKYO-JAPAN
044(244)2151
EXTENTION 304
SYSTEM DESIGN
IKEGAMI CO. LIM.
(Ikegami was the company that Nintendo hired to do the actual programming on Donkey Kong, and actually won a lawsuit against Nintendo about their ownership of the code. This is why the arcade version of the game is so rarely re-released)