Insert a memory card with a saved game from DDRMAX: Dance Dance Revolution. Enter the options screen in DDRMAX2: Dance Dance Revolution and select "Memory Card". Then, select the "Support" option.
Hold X to select a song. Keep the button held until an extra menu appears that allows the song to be played differently.
Get an "AA" rank on the last stage on Heavy mode to unlock the Extra stage.
Unlock the Extra stage, then pass MaxX Unlimited with an "AA" rank with 1.5x speed, reverse scroll, dark mode, and pressure mode to unlock One More Extra stage. Alternately, get an "AAA" rank on the last stage on Heavy mode.
Get an "AA" rank on any song on Heavy mode before the final stage to unlock the Paranoia Survivor stage.
Pass the Extra stage to unlock the Maxx Unlimited stage. If you do not have the Maxx Unlimited stage, you can get it on roulette if you are lucky. Additionally, use the following trick get Maxx Unlimited before it is normally unlocked. Select "Roulette" and let it go around at least once. You will notice a song in red; it is Maxx Unlimited. When the roulette gets close to it, press X and hope for the best. Note: Maxx Unlimited is the most difficult song in the game.
Unlock every song available in the game menu to unlock Endless mode. In Endless mode, you will play every song on the list nonstop.