Sega Master System / Mark III / Game Gear
Hold on controller 1, and press on controller 2 to increase the starting level. Pressing on controller 2 will decrease the starting level. You will hear a tone when increasing/decreasing the starting level. Press on controller 1 to start the game after selecting your starting level.
Pressing or on controller 2 at the title screen will change the difficulty setting, which is added to the bottom of the screen.
See the main page for Dead Angle