Press green flag TWICE. WASD/Arrow Keys to move. 1,2,3 to select BG Space bar to shoot. If cards pop up by the HP reading, press M for mega shot. You get 3 hits, then you die. Keep shooting the boss until He dies. He will change form every now and then. Don't touch THEM or get hit by THEY'RE obstacles!
MARIO'S TUNNEL OF A DOOM!