There are a confirmed total of 5 Main ACTs in the game. The after game has more but they aren't just side story either. It's also main ACTs, but it's after the main story is completed that it will continue. There are a total of 53 main game bosses. Around 16 dungeons with their own set of challenges and even an enormous amount of enemies to count. But there is one special thing. A Encyclopedia for the monsters and bosses. But to obtain it you must first, find it. {Once the game releases of coarse)