… after clicking in a blank area of the screen while a YouTube video is running.
Defend the YouTube from attack!
Ha, fun.
Cool. 
I ain’t doin’ it till someone tells me what to expect!
All I get is that each digit jumps you to a different part of the video - 1 takes you to the 10% mark, 2 to the 20% mark, etc. 1980 just jumps you around then back to the beginning.
Click somewhere blank, like in the white space below the video down where the description is, then type 1980.
Me too
Ah, live a little!
That was actually kinda fun…
It’s a playable version of Missile Command.
Damn programmers with too much time on their hands…
That’s very funny. 
That is really what it is Gato.
It just paused my video and made a big blank space above it, and caused my cursor to disappear.
Is it possible to win?
That was cool. Unfortunately, Sheldon and Penny in the jewelry store did not survive the attack, so nobody watch that clip anymore.
I never did like that game too much. I’m a “pinball man”.
Jeez…that’s a lot faster than I remembered! (Or my reflexes are 30 years older…)
Yeah, it’s not just you. Damn.
Also, type “1337”. The comments improve greatly.