Okay, so it's pretty obviously a Dr. Horrible origin story. Captain Hammer is really a putz. Penny is, um, well, um. I was thinking about how much I knew about Bruce Wayne's parents way back when I started reading Batman. (Maybe not the best example but it was the first one I was thinking of because of that new movie.)
You know, the love triangle thing would have been good for several more episodes. Given how weak, I felt, Act III was relative to the other two, Penny's fate seemed a little trite. But, then, it was about 45 minutes long. Think about how many bad first episodes (or bad first issues) are out there.
But, he got into the Evil League of Evil. Score!