Parts in games where you're thrown into something completely new/daunting/overwhelming and have very little time to adapt to it.
>Mario and Luigi: Superstar Saga
>final boss is a two-part, once you "beat" the first part you get knocked out and fight the real final boss
>starts you off on 1 HP and the boss always attacks first
>losing sends you back all the way to the first part
>Halo Reach
>Defend the Pillar of Autumn long enough so it can get off Reach
>credits roll
>one last mission
>"Survive"
>there's no way to win, you just hold out as long as you can
>when you "die" cutscene plays of your spartan going full tardrage on the remaining covenant, kills a good number of them before finally going down