Why are the bosses so damn hard to figure out in this game!? The stages are no problem. The mid bosses (which so far mostly comprise of the same guy in different situations) are not much of a big deal. But the Act IV bosses? Holy jeebies! Other than having 4 or 5 energy bars, they are mostly impervious to damage until they show some type of stall or weak point.
Now I'm not truly complaining, because I eventually defeat the bosses. I suppose I'm just in a rush to win, as the boss levels seem to take just as much time to complete as the standard levels (8-11 mins).
I'm currently on Reel 3, Act III, and it seems that there are six bosses, just looking at the flybys in the opening video.