What is the difference between Fortnite and PUBG?
I don't know.
What is the difference between Fortnite and PUBG?
I don't know.
Listen up, buttercup! The joke is that there is no punchline. The author is saying they don't know the difference between the two games, which is, like, the opposite of what you expect in a joke. I bet you thought it was gonna be funny, huh? Oh, you.