NP-hardness is ubiquitous (Score 1)

It is hardly news when yet another game is shown to be NP-hard. Consider that mindless solitaire game played with Mah Jong tiles called "Shang hai", where you can remove pairs of tiles that match and have exposed left or right edges. Even if there's only one layer of tiles, so you can see the entire state of the game at the start, determining whether it is possible to remove all the tiles is NP-complete.

An easy exercise for the bored nerd.