Thank you for detailed feedbacks!
> too much repetition
Now I can agree.
>if the effect was more dramatic it would be better
Honestly,I don't love too dramatic effects which can be seen in many other games.
But I agree I should decorate this game more.
>once you solve a puzzle executing it should be as painless as possible
>another nitpick is that jumping is too unforgiving
I know these are related problems.
Bad control is caused by lack of my code experience.
Giving a "grace period" or some improvements like that will help definitely.