This episode contains great action and great dialogues. My favorite guest star of the whole series has to be Professor Palmer.
Palmer has a great sense of humor. I love the opening scene of him and the light banter between him and his assistant, Katie. And he takes everything in stride; the way he took out the 'serpent', and is seemingly unfazed when Superman asks for his help.
It also helps that he is voiced by John C. McGinley, who plays Dr. Cox on Scrubs.
There are great character moments for most of the heroes as they try to slow the machines' march toward the nearby towns, and from there, the rest of the world. The JL drew a line and by god, nothing will cross it. It's great to see the heroes use their powers in an all out fight here.
Beside the action, there are numerous little humorous bits sprinkled throughout the episode, as is the standard with this show. I -love- how calm Batman remains as he plunges toward the ground, his voice level as he calls for backup. At the last second, Superman drops by and the Bats resumes the mission as if nothing happened.
Of course, there is a potential crisis here and the seriousness of the situation is not lost. There are a few grim moments (the implication of using -people- as raw material to make more machines is creepy) and some tense scenes as the battle rages on.
Overall, it is a great showcase of our heroes using their skills in tackling this enemy, be it powers or brains, or both, and the characters delivered quite a few good lines. The introduction of The Atom is the highlight for me.