Not heard of this Nes Homebrew Game before but heres more details:

MashyMashy is a NES “game” for measuring mash speed. Possibly more of a tool than a game, it allows you to choose a mash button and time limit, then you mash to your hearts content. Afterwards, your total hits and rate of button pushes per second are displayed.
It was written by Mitch3a as a way to learn core NES development concepts (mostly based on nerdy nights tutorials) while writing something useful, especially for the speedrunning community. It was started about a month ago and is considered complete.

Full info here -->,23451.html