Daiku no Gen San 2

Stage Select
Press Up, Right, Down, Left, Up, Right, Down, Left when the "Irem" logo appears on the screen, then just start a new game. The "STAGE" screen will appear after the title screen. Press A or B to change the stage number, and press Start to begin the selected level.

SE Test
Press and hold the A button on the second controller before the title screen appears. You can either wait for the intro cutscene to end or just skip it by pressing Start. Press Up or Down to select a sound effect, and press A to play it.

BGM Test
Press and hold the B button on the second controller before the title screen appears. You can either wait for the intro cutscene to end or just skip it by pressing Start. Press Up or Down to select a music track, and press A to play it.