Rovio released the original Angry Birds on the App Store on December 11, 2009. Angry Birds Chrome brought that formula to browsers in 2011. The current build retains Chrome-branded loading and menu art as well as the HTML-era GWT and PlayN technology used by that web edition.
The episode menu combines selected chapters from the original game, including Poached Eggs, Mighty Hoax, and Danger Above, with Seasons sets such as Season's Greedings. It is an archived Chrome web snapshot, not a complete copy of every mobile update, later sequel, or commercial service.
Each level gives you a fixed queue of birds and a structure protecting one or more pigs. Clear every pig before the birds run out. Direct hits, falling blocks, and chain reactions add score, while unused birds help push the total toward the level's three-star thresholds.
Birds do not all behave alike. Some rely on impact alone, while others have a mid-flight power. Read the bird order before shooting, then match the launch angle and ability timing to the structure rather than repeating the same arc.