This one felt really annoying to me, guess I'm not a big fan of this mechanic. Anyways, I got S+ in my ~40th run and after that realized there was a heart in this level ._. Welp, now I've learned to check for that before playing...
Also, at the beginning of the level I was testing how broken the mechanic that lets you jump over any obstacle is. Just swing your mouse fast enough and you can even 'dodge' solid objects. I really feel like there should be some sort limit for how fast your cursor can move in this game. Otherwise people will be just cheesing all the hardest parts using that.