How about this one: Games that switch genres at the 11th Hour. I can't remember which game it was, either Two Worlds or its Sequel, both terrible games. But in either case, I'm playing an RPG. I've spent many hours in-game, levelled up many times and gained many skills. Skills mind you, that I'd hope to be able to use in the final boss fight. I should be awesome and all-powerful and... and... wait, are you kidding me?? In their infinite wisdom, the developers decided the final boss had to be some target practice against a flying dragon using mounted artillery points, and you couldn't use your skills at all. None of it figured into the battle. It stopped being an RPG at that point, and I remember it peeving me to no end at the time. It's not fair to the players and the time they've spent on it, to say, you know what, this doesn't matter anymore.