How do I implement api for level based game?

[TwinkleStarGames]

Hello, I want to submit my game Electric Box 2 on mindjolt, which is a
level based game. You can see the game here:
http://www.newgrounds.com/portal/view/548266

I am very confused when should I call the score submit method. After
all 40 levels? Or after every levels or after every 10 levels?

Thanks