Tile M for Murder (2007)

"A disillusioned man attempts to murder his wife through a board game."

It's a hot day, and Dave hates his wife. He should be out doing exercise, spending money, meeting people. Instead, he's playing word games with her. At this point, Dave is a prisoner of marriage until the day he dies. He's losing hope and losing his marbles. But, as the game continues, a series of ironic events lead him to realize that what seems like just a stupid, old board game might be the key to his escape or, for that matter, his downfall.