How do you get 5 stars in sonic and the black knight

I happen to be a bit stuck on this too, I'm currently searching, so far I've learnt that to get 5 stars you need to kill all enemies, and hav a good chain, equip items most beneficial t the mission and time doesnt matter, though of course it doesnt mean you take it easy XD hope this helps for now, I'll update when I find anything else ^^