Ball Mode, Theater Mode, 9 Lost Masters
Beat arcade mode with the following characters: Xiaoyu, Yoshimitsu, Nina, Law, Hwoarang, Eddy, King, Paul, Lei, Jin. Note: The easiest way to do this is put the game on easy and 1 round.
Submitted by Sam. 100% success rate. 

Jack's Tank-Top
Beat 10 rounds of ball mode with Gun Jack.
Submitted by Sam. 

Tekken Ball Mode
To access Tekken Ball mode, beat the game with all regular characters.
Submitted by Eddy_G. 

Unlock Doctor B.
Beat Tekken Force mode 4 times to unlock Doctor B.
Submitted by Sameerahmed. 

Go to: Tekken 3 Info Page | nGaming Home Page.