The NP ratio tells you how many Neopoints you'll earn for every point you score while playing a game.
For example, if the NP ratio is 100 NP for every 150 game points scored, to earn the maximum 1,000 NP reward for playing, you'd have to score 1,500 points during the game.
On the other hand, if a game's NP ratio is 25 NP for every point scored, you'd only have to earn 40 points in the game to get the full 1,000 NP for playing.
Clockwork Codebreaker:
Figure out the correct order in which to place the runes. You'll have 12 chances to guess the code. Click on the gears to turn them and line up the runes in the order you choose. Then, when you've created your code, click on the red button in the centre of the gear to check it.