The name of the game seems to be a pun on the PPSh, a WWII submachine gun.
It could also just be the phonetic spelling of "pew pew" in Russian.
And it is.
The 'sh' is only a hint about the language (shell).
Piu-Piu-Sh: ‘Shoot Them All’ Game in Bash
11–12 of 12 posts
Re: Piu-Piu-Sh: ‘Shoot Them All’ Game in Bash
#12Not as spectacular, but allow me to plug my Arkanoid clone for bash: