I always excused the game's puzzles saying that I'm really stupid, and actually LOVED some of them and how they are so much fun... but the fireflies and mushroom one is absolutely BOTCHED.
Two physical objects, on a slope. The flies can ascend the obstacles, the mushroom rolls down away any hill or slope, making the fireflies go around and away them back towards their home.
The bugs go homing back to the starting point desperately, and that kinda makes them stick to walls, where one can't do much. Same with the dropping of the mushroom, since it lacks precision. I found myself against a wall with the damn insects way too many times. I tried telekinesis but it didn't work with the mushroom.
SOMEHOW, out of absolute spite I managed to finish the last one, near the roots. (I can't say it's the worst one since there's the one just around the starting point) but before picking the last flower up, the cutscene started, leaving the screen with a permanent "E" on the bottom. (I got rid of it reloading the game from a save with it)
Keep going with the rest. It looks gorgeous, and the models and animations are great!