Because it's nim + omino = nimomino, which is utterly unpronounceable but sounds kinda like Nanaimo.
As the game is based off nim, I beleive it inherits some of the same properties. For example, I think that as long as the board-size is multiple of the maximum move + 1 (e.g. a tetromino on a 5x5 grid, used in the demo) then the first player always wins. This is simply a back-of-the-napkin hypothesis and I would love for someone to prove me wrong.
This was written in one night, fueled by pure insanity. Everything about it works, and nothing more than that.
To simply run it on a local machine, run npm start to spin up a dev server.
To publish to github pages, run npm run deploy and hope it works.