I don’t know if anyone has made this into a game yet, but the climactic fight in Avengers: Age of Ultron is a tower defense level. Avoiding spoilers: the Avengers end up protecting a button. If one enemy gets past them to push the button, the bad guys win. Arrange the Avengers around this button (in 3D – superheroes fly!) and stop the bad guys. Uh oh, here comes Ultron — boss wave!
Spoilers are allowed in the comments, so feel free to discuss the fight, the movie, tower defense, etc. And you may not want to click through to comments if you want to be surprised at the movie.