With the all new Angry Birds game, Angry Birds Space, launching on Thursday, players who have completed every single level the Rovio has thrown their way are salivating at the idea of brand new content. And if you want to unlock the first bit of bonus content in the game, you’re going to have to go through Walmart to do it.

Walmart and Rovio have announced their “first retail and gaming integration,” and it involves bonus levels, merchandise, and Facebook. Tomorrow, March 22nd, Walmart will start giving clues to their 13.7 million Facebook fans about how to unlock four bonus levels inside Angry Birds Space. They are calling these clues the “Golden Eggsteroid” clues.

“We wanted to give our fans a unique retail extension to Angry Birds Space that rewards them for their eagle eyes,” said Peter Vesterbacka, chief marketing officer and Mighty Eagle of Rovio Entertainment. “Only Walmart can deliver the reach across America for this type of program and we wish our fans luck as they seek out our hidden clues.”

Indeed, a Rovio / Walmart partnership now feels titanic, something that Rovio could have only dreamed of when their developers launched that first bird into the first pig.

Facebook clues are only one part of the integration. The real mass behind this partnership is on the merchandise side. More clues to unlock content will be hidden in Angry Birds products, available as Walmart. Stuff like plush toys, snacks, and apparel will have secret codes hidden on tags, boxing, or even within the design of the products themselves.

“Walmart is bringing fun back to the shopping experience, with interactive merchandise that brings the best of digital gaming together with in-store retail,” said Seong Ohm, senior vice president and general merchandise manager for entertainment, Walmart U.S. “By partnering with Rovio, we’re able to give millions of avid bird slingers bonus content by coming into our stores and shopping our broad assortment of Angry Birds Space merchandise. This is just one of many exciting partnerships Walmart is forging to give our customers access to exclusive content.”

What do you think about this partnership? Will people buy Angry Birds merch in order to unlock bonus levels in the new game? Let us know in the comments.