After disassembly some short reverse engineering session ensued. All the buttons were mapped to their corresponding controller pins.

Take note of the 4 thick traces on the left of the COB. These are the game selection jumpers.

If shorted to ground the game is changed (You need a different LCD for that). This orange one is Soccer. I had Racing and of course City fighter (Brawler). City fighter is selected when no jumper is present.

That leaves an option for a 4th game. I wonder...