I _finally_ managed to get a medal on the final level, the one that it only beat least night by turning on the infinite lives cheat and using _35_ lives to finish!!
I'm just no good at these types of games, not when it comes to performing to the level of flawlessness they require for you to get golds. And of course there are some ships and levels that can't be unlocked unless you get all golds =P
I need to just give up and invest in a game shark at some point and cheat a hell of a lot =)