The new Super Monkey Ball game for the Nintendo 3DS will let you unlock a character in the game if you walk around a lot with the 3DS. The price is 20 3DS Play Coins, the currency Nintendo said would be earned by any 3DS owner for the steps they take each day.

The 3DS is able to track a system owner's steps using a built-in pedometer. The Play Coins are tallied once the user takes a 1000 step in a given day. Nintendo is letting game-makers offer rewards for those coins. Sega's choice: to let people redeem 20 of them for an extra character in the Monkey Ball game.

A Sega rep who told me about this wasn't sure if the unlocked character would only be available through Play Coins, but guessed it wouldn't be. He also said that Sega testers have no way to cheat the system and earn coins in a hurry, so they've been spending time shaking 3DSes in the air, trying to simulate steps. He says it took a couple of hours to earn the 20 needed for an unlock.

What would you want Play Coins to unlock in your games?

Super Monkey Ball 3D will launch alongside the 3DS in the U.S. on March 27.