WipEout HD is hard. If you've played the game, you probably know that and, if the newest patch is anything to go by, the developers at Studio Liverpool have also realized this. Updating the game to version 1.20, which will happen as soon as you start the game, will make getting medals in campaign mode a lot easier. You can now change the difficulty setting within campaign mode to novice, skilled or elite, just like in other modes. This changes the medal requirements, making completing the game a much simpler experience.
It also means the difficulty ramp for the game is far less steep, as you can blitz through on novice, then change up to skilled and then, eventually elite. The medals look different for each difficulty, so you can clearly see on which mode you've completed each task. This doesn't help with the most difficult trophies, but at least completing the game is actually possible for normal humans. So, if you haven't played WipEout HD for a while, give it another go. You might get sucked in all over again -- we certainly did.
[Thanks to everyone who sent this in]