Google is starting a new Android initiative to drive in-game sales called Collectibles Week. For one week only, twenty five games will have new content that can be unlocked or bought in-game. Some of the items are Android-themed, such as a special Android monster for Monster Park, while others are seemingly unrelated, like a new patio set for The Sims.

This is the first time we can remember Google — or any mobile OS maker — actively encouraging developers to offer limited-edition content, Zynga style, for their games. The promotion runs until next Friday and has separate app lists for both US and international users.