THE FLOCK WASN’T due to strike till Valentine’s Day. But contrary to earlier official word, “Angry Birds” for Facebook has been uncaged a day earlier.

“Angry Birds” is loosed a day early. (ROVIO / Facebook)

To lure players to fly to Facebook to play, the Flash-based game now has “in-game” options, according to Rovio, its Finnish developer.

“There are 4 different types of power-ups” — from Super Seeds to King Slings — that are “unique to Angry Birds on Facebook ... ,” according to Rovio. “All power-ups have a different effect but ultimately make you more competitive against your friends by making your birds stronger or more accurate or even by shaking the earth itself!”

(No word on whether the game’s swine can try to flee to FarmVille.)

Naturally, the game also allows you to engage/goad/humblebrag-to your Facebook friends with your high scores and crowns, according to Rovio — and you can also gift them with power-ups.

Rovio, of course, is hoping for the ultimate power-up by migrating to Facebook — what better way to feather the game-maker’s nest of global domination/monetization?

Without further ado, you can play the game, if you dare, by clicking HERE.