7. Army Of Two - Killing The Final Boss In A Cutscene
The first Army of Two, back in 2008, had so much going for it that it could have really set the bar for cooperative gameplay. A cover-based shooter with a buddy, as two wise-cracking mercenaries; it had the potential to inject some life into the genre.
Whilst it did deliver on the potential with some pretty decent cooperative gameplay, it fell for the modern trappings of so many games: all the best action happening behind a cutscene.
There's nothing more frustrating than putting all the legwork in, either by yourself or with a buddy, only to have the game sit you down and say, "Don't worry pal(s), we'll take it from here".
This is particularly annoying when it comes to the final mission of the game, when former aide-turned-traitor Clyde is hunted down, with the killing blow being a scripted kick out of a window. But then AoT doubles down with the final "battle" against Richard Dalton, your former leader.
Instead of a climactic battle, he's just blown out the sky in a cutscene.