I got 5 stars with my main yesterday and I was slow because was making dinner at the same time and went to the kitchen from every now and then. I did 30 minutes more than the time limit, time is not important. You have to avoid all traps, if you’re hit by a trpa your score go down, also you have to empowered when there are alot of mobs you can kill within 20 seconds, I¡m sure you wait for the elites to empower you, that’s a loss if you don 't kill them quickly.