Zombieland's opening is horribly inefficient. It distrusts the audience, undermines its punchlines, over-emphasizes Columbus's rules system, and improperly introduces him
I was rewatching Zombieland and the first 10 minutes really fell flat for me, and I realized it was because the gas station scene is just functionally repeating everything we've already been told by the cold open. The cold open gives us exposition about the world and introduces us to his rules system, and he says he survives by following said rules. The rules are illustrated by a bunch of random people dying for not following said rules, while Columbus provides commentary over it.
Then we get an opening credits sequence set to For Whom the Bell Tolls, and THEN, five minutes into the movie, we finally meet Columbus. Again, he tells us through voice-over that he's survived because he follows the rules, which we know already. Then he has a run-in with some zombies, and the rules are superimposed on the screen, and he just follows them. This scene is flat and tensionless, because we're learning absolutely nothing. It tells us nothing new about Columbus, and in fact is an inefficient character opening for him, because it's (probably) meant to make him feel vulnerable and endear him to us, but the cold open has introduced him to us as this narrator-sage ambassador for the human race.
The gas station scene should have opened the film, then some of the voice-over from the cold open (commentary about the rules) can stay, because it adds personality, and that way it achieves two things at once. Plus, it makes our introduction to the zombies directly relevant to our protagonist, instead of a bunch of random people we won't see again. When he's running from them in the gas station, we don't feel like he's in danger because he's already been established as this rigid rule-follower.
Making the gas station the first scene and introducing him to us via his direct adherence to these rules also better sets up his arc... his rules are designed to make him self-sufficient and not dependent on anyone, but his arc ultimately culminates in him breaking his most important rule to help someone he cares about