Koopa is Bowser. That’s his name in the original Japanese and we used to call him that internationally as well. If you had been a fan when the movie came out you’d have mostly played games and watched cartoons where his name was Koopa.

And what do you mean it wasn’t endorsed by Nintendo? Nothing that’s in the movie is there without their explicit permission. The studio literally asked permission to make it dystopian cyberpunk and got the okay. They put their faith in the movie industry to turn out a good movie. That may have been a hilarious mistake but it was Nintendo’s mistake.

My answer is Battleship. It was a bad idea to even try.