Drain opponents health
After putting in the code for level select begin a fight. Hit your opponent 1 time and after that you can hold down the L and R buttons to drain his/her health! You must hit your opponent at least once for this to work. The only way to get rid of this code is to delete the Samurai Showdown memory from your 3DO system.
Same color opponent
Start the one-player game, then join in with player two and pick the player the computer was using. Kill player one. Do not continue and your character will start with the one-player game again. Join in with controller one, and again pick the same character the computer was using. Kill player two. When the next one player game starts, your character will be the same character and color as the computer.