Woody Harrelson is in full blown crazy mode which is always fun and Jesse Eisenberg is in full blown virginal nerd form which he does so well.
The British version of this is "Shaun of he Dead" which is set with an equally confused protagonist and some very British emotions that work so well in a long line of crazy comedies.
Well it started many years ago with George Romero's very original and daring movie "NIGHT OF THE LIVING DEAD" which set the standard for the zombie apocalypse.
However, recently, I think it traces back to THE LIVING DEAD as graphic novel (comic book), World War Z, and "Forest of Hands and Teeth" and "Pride and Prejudice and Zombies" and "Married, with Zombies" and a number of other books and novels.
It's one of the horror genres that explode every so often.