I prefer the hard difficulty more than easy beause the fish is slower so it brakes firmer so you dont fly off into a enemy fish, its good because the speed is capped and i get much further into the game with it
Go at maximum speed to earn lots of points quickly and collect coins, you'll be going so fast you'll barely get any OWs, make sure you avoid the long obsticles or they will make a big dent in your score and probably lower it down to 0 again