I can play Half-Life 2 on Hard reasonably.
I did Cave Story on Normal up to the boulder. After that, trying to move forward felt like slapping a brick wall with a rubber chicken, so I changed my save file to Easy and the game felt perfect for once. No longer did I need to set my health to 255 to beat the Core. All my problems with the game, aside a few maddening unpredictable things like having to talk to Curly twice in the lodge even though the dialog from the first interaction implied I was supposed to go on without picking her up at that moment and later realizing I had to change my save file to put myself back in the lodge and get her again in order to be able to go to Hell, seemed to have disappeared. And then I realized now that the bonus features would only be fairly attainable if I did the whole game again in impossible mode.