#5 Metroid Prime 3's Slow-Opening Doors
At first we weren't sure about this one. It seemed like Metroid Prime was glitching. Did the developers forget that when you shoot a door it should open? Eventually we realized that the delay between shooting a door and it opening was, in fact, an improvised loading screen that would have you standing idly by for up to five secods. This occasional, yet unbearable wait became even worse if you were trying to escape an enemy-filled room rather than just running about in a fit of exploration.