Hint :
Model Mode:
To unlock Model mode, finish the game on both Easy and Normal difficulties.

Sound Test:
To unlock Sound Test, finish the game on Easy, Normal and Hard.

Unlock Harder Skill Levels:
To play a harder skill level, finish the game at an easier one. For instance, completing Easy will unlock Normal; and Normal will unlock Hard.

Final Synchronized Dance Move:
On Mission 5 (the synchronized dance between Eva-01 and Eva-02) you may have noticed that there are 8 bars indicating 8 dance commands. However, the game only tells you the first 7. To do the 8th, and to do the dance completely and correctly, simply push the C-up button three times when the 8th command bar passes through the green zone (or if you can't get the timing right, just keep tapping the C-up button after you've finished the 7th command). This will show the two Evas standing after the Angel is destroyed, instead of lying on top of each other.