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.
Revel Roundup:
The citizens of Shenkuu need Snorkles for the Lunar Festival celebration, but those wily Petpets have escaped! Orrin must hurry around collecting the Snorkles (plus some Festival goodies along the way) before the proceedings begin! Watch out for items and other Petpets that aren't on your list. If you happen to pick one up, you'll have to give it to Anshu before continuing on.