If you're in 'Canada' go for high appeal assets. I just got 5* in Jurassic difficulty with a Spino, Rex, Giga, 2 tylosaurs, a mosasaur, metriacanthosaurus, 1x brachiosaurus, 2x camarasaurus, 2x carnotaurus and a mix of struthiomimus and gallimimus (just to reach the minimum of 11 species).

You're gonna need a well organised monorail, and strategically placed amenities with adequate restrooms and shelters to get to 5x. The storms are annoying but if you've got enough cash reserve they don't really matter. Fire the scientists you don't need and only keep enough to clone the 'big 3' ie rex spino and mosasaur.

I know it's easier said than done. Took me over 20 hours but I got there lol