Get the five hidden sandwich ingredients in a level to unlock a mini-game.
On level 2, to open the bridge there are four switches. Press switches 1, 2, and 4.
The safe which is in the bank has a three digit code. The code is "1-3-7". It can be found written on the blackboard in the schoolhouse.
You must turn on all the sprinklers, then use the Tomb Of Doom. Note: You will need full power.
When you go in the elevator and go through into the room with the panel of green covering the door, go to the control box on the left. Press the first button once, the second button twice, the third button twice, and the fourth button once. You will be able to walk through.