this is interesting, level 10-3 on heavily, I had 4 m 863k points, 7 daimonds, but only rank A, but when I set bullet speed +5%, it gives 10% extra points, I got 3m 561k points, also 7 daimonds, much less points, cause I had less bullet clearing, but I got one star rank. I'm susprised, that I did one star ranking in so much levels, it means 43 from 50, when I played this game in march 2019, I tried to do stars in first world on heavily, but I got it only in first 3 levels, then I decided to do hard badge, I got it after doing world 7 and I stopped to play this game for a long time, but I sometimes like to play in games, when avoiding is very hard, I'm addicted,I had 30% one star ranking, then I removed progress to avoid this game, but it doesn't give anything, I think world 6 is second the easiest world, boss also isn't so hard like second one.