Dancer In Background
The 3rd secret that you unlock is the option to have a dancer in the background. 
This is modified in the options menu, and can be turned off or set to a new person, 
including DDR originals like Disco and Akira, plus the artists like Naoki and U1. The 
dancer will just dance accordingly to the song you are playing, but doesn't work 
with Music Videos.

Extra stage:
Get an "AA" rank on the last stage on Heavy mode. 

One More 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. Alternately, get an "AAA" 
rank on the last stage on Heavy mode. 

Paranoia Survivor stage:
Get an "AA" rank on any song on Heavy mode before the final stage. 

Maxx Unlimited stage:
Pass the Extra stage.

Endless mode:
Unlock every song available in the game menu. In endless mode, you will play 
every song on the list nonstop.

Unlock all DDRMAX bonuses: 
Insert a memory card with a save dgame from DDRMAX: Dance Dance Revolution 
6th Mix. Enter the options screen in DDRMAX2: Dance Dance Revolution 7th Mix 
and select "Memory Card". Then, select the "Support" option.


Unlockable Songs
Here are the unlockable songs and how many points you need to get them: 

1 - 05 points - Try 2 Luv U. - S.F.M.P. 
2 - 10 points - Put Your Faith In Me - Uzi-Lay 
3 - 15 points - Unlocks Dancer Options 
4 - 20 points - think ya better D - sAmi 
5 - 25 points - DIVE (more deep & deeper style)- Be for U 
6 - 30 points - Can't Stop Falling In Love - Naoki 
7 - 35 points - Nonstop course #7 - RMX of LOVE 
8 - 40 points - Silent Hill - (3rd Christmas Mix) 
9 - 45 points - Don't Stop (AMD 2nd Mix) 
10 - 50 points - Tomorrow Perfume - dj TAKA 
11 - 55 points - Kind Lady (interlude) - OKUYATOS (Oni Steps) 
12 - 60 points - Burning Heat! (3 Option Mix) - Mt. T with Motoaki.F. 
13 - 65 points - AM-3P (AM East Mix) - KTz 
14 - 70 points - End of The Century - No. 9 
15 - 75 points - Nonstop Course #18 - Player's Best Long 
16 - 80 points - more deep (ver 2.1) - Togo Project feat. Sana 
17 - 85 points - Vanity Angel - Fixx 
18 - 90 points - Do It Right (80's electro mix) - SOTA feat. Ebony Fay 
19 - 95 points - SP-Trip Machine (Jungle Mix) - De-Sire 
20 - 100 points - I Need You - Supa Fova (Feat. Jenny F.) 
21 - 110 points - Maxx Unlimited - Z - red 
22 - 120 points - Nonstap Course #9 - RMX of TRUTH 
23 - 130 points - Super Star (from nonstop megamix) - DJ Rich feat. Tail Bros. 
24 - 140 points - PARANOiA KCET (clean mix) - 2MB 
25 - 150 points - Bad Routine - DJ Spugna 
26 - 160 points - Radical Faith - TaQ 
27 - 170 points - Hysteria 2001 - NM 
28 - 180 points - Afronova - Re-Venge 
29 - 190 points - Forever Sunshine - Chel Y. 
30 - 200 points - feeling of love - youhei shimizu 
31 - 210 points - CELEBRATE NITE Euro Trance Style - NMR 
32 - 220 points - Nonstop Course #15 - Ultimate 12 
33 - 230 points - Xenon - Mr. T. 
34 - 240 points - Kakumei - dj TAKA with Naoki 
35 - 250 points - Endless Mode 

Faster Unlocks:
As the manual says, unlocks are made by earning "points" in-game. So far I only 
know you get 1 point per player per song. Also one point per player for accessing 
the Extra Stage (AA or better on your last song on Heavy Mode with Event Mode 
turned off). First, go into option mode, and set the play level to "easiest", the 
number of songs to 5, and (if you have no confidence in your game), the "song 
failure"-type option to "end of music". Now you're ready. Play the game, and set 
up to versus play. Make sure you have 2 controllers. These can be pads or hand 
controllers. Play any songs you want to. Make sure that both players score though. 
This SHOULD earn you 10 points per set. If you want to earn 12, play an easy 
song (7 feet or less) on HEAVY mode, and AA it. This will take you to the Extra 
Stage (Maxx Unlimited) on Heavy mode, reverse scroll, dark mode, 1.5x arrow 
speed, etc.. I can't name them all. As long as both players score, you'll earn 12 
points. IF by some MIRACLE you AA THE EXTRA STAGE, you'll go into the ENCORE 
EXTRA STAGE or something like that (I never made it that far), which is "Kakumei" 
And should earn you 14 points in total. I'd suggest trying to earn 10 points a set, 
which will earn you 1-2 unlocks per set. "Kakumei" is unlocked at 240 points 
and "Maxx Unlimited" is unlocked at 110 or so.

Unlock Silent Hill: 3rd Christmas:
Silent Hill: 3rd Christmas Mix is the 5th secret you unlock. WARNING: This is A LOT 
harder than the regular Silent Hill, for it is faster and MUCH more complex. I 
sugest you master the original in Heavy mode, with 2 pads if possible, then start 
training with the 3rd Christmas. It's THAT hard.

Extra options:
Hold X to select a song. Keep the button held until an extra menu appears that 
allows the song to be played differently. 

Get Points Easily:
Having trouble getting those points to unlock new songs? Play in 2-Player mode to 
get double the amount of points. Even if you don't have another person to play 
with, just plug in another controller anyway. You still get double the amount of 
points if the other player fails.