The short is an interesting psychological character study and if you don’t think about the full length film it eventually led to, it presents a great opportunity to see both the stars showcase their diversity in acting. While Jay is at his neurotic best, Seth moves away from his comic-boy persona and gives quite a performance. Since this is a film being made by friends there is a hint of sarcasm in the acting, but never does it cross the boundary between serious acting and over-acting for the sake of comedy.
The most interesting aspect about Jay and Seth Versus the Apocalypse is that when you look at the film that it inspired, there is quite a contrast between the two in the overall tone. While the short is more of a psychological horror with a hint of monster madness, This is The End relies heavily on the comedy and the absurdness of the situation. Both films stand tall in their own departments, but the progression from the script of the short to the film would make for quite an interesting study. Another minor point that is noticeable is the somewhat role reversals we see between the two films. While This is The End sees Jay Baruchel as more of the “hero” in the group, it is Seth Rogen who is more domineering in the short.
As it’s only 10 minutes of your life, I highly recommend that you watch the short, if for nothing else then to compare and see how it has transformed into a film that was one of the sleeper hits of the summer.