Kizuna Encounter / Super Tag Battle
This game not only pioneered the introduction of a tag system for the fighting game genre, but it also initially tested as a 4 player MULTI-LINK title. The released version of the game actually contains the programming code for this option and can be accessed and viewed with a debug bios chip. However, without the special dual jamma connector interface board, the functions and controls for players 3 and 4 cannot be utilized properly. A picture of this unique board can be seen below. Speculation tells us that World Heroes was also initially intended to use a MULTI-LINK feature as well, but this has never been proven and the released programmed version does not appear to contain the data. Either way, it is pretty safe to assume that the cartridges were not assigned altered game codes as was once considered a possibility.