On most stores, you can flag games or apps for copyright infringement and if you have proof (like yours was published first and they stole the assets), the copy version will get taken down.
It's not something that should be a cause for concern because almost every game out there has ex-tractable assets. Even complex 3d ones, I can get their models & textures, I've been modding games for fun ever since 1995.
In the industry, the copycats are what's called "Reskin Industry", they take your game, the code, and replace your asset with modified ones or other theme variants, then republish that. They get away with it, because you can't accuse them from ripping your assets, you also can't copyright a GAME idea or game playstyle. Anyone can make a Mario clone as long as they replace the art.