APK = the engine. OBB = the entire world.
⚠️ : The game was officially discontinued and removed from Google Play and the App Store around 2018–2019. Online features no longer work. angry birds action apk obb
Because the APK is small, the bulk of the game's high-quality assets (graphics and levels) are stored in an OBB expansion file. Without this file, the game will usually hang at a "Checking Expansion File" or "Download Failed" screen. APK = the engine