March 29, 1996
Tekken 2 features a secret gameplay mode that might be based on Punch-Out!!, accessed after all characters are unlocked by holding L1 and L2 while selecting a fighter. Once this mode is activated, the player's character will change to a green wireframe, and the camera will move behind their back during gameplay.
This mode is therefore almost identical to the original arcade Punch-Out!! gameplay, but it was never confirmed to actually be an intentional reference, rather than a coincidence.
The reators of Tekken 2 held no right over Nintendo's Punch-Out!! but they only included a minor reference to the game.