Invincibility:
Press Up, A, Right, B, Down, C, Left, Start at the title screen.

Jump to level 8, stage 3:
Enter the options menu. Change the controller configuration to A and C for fire and B for jump. Return to the title screen allow demonstration mode to begin. A very dark level will appear. The demonstration mode will eventually freeze. Press Start to enter the game. Toki will die and restart at the Volcano level. Note: Keep spitting to see this level.