Hardness makes a game worth while. THe hardest bit? Ravage rider. Took me 2 weeks to beat it, but was still fun.
Dotd was hard in some parts, but not fun hard. Stupidly hard.
Dawn of the dragon is kind of hard on the first time through and it kind of still is without a enemy health system. But I really lost interest in Spyro a few days ago because of it.