Good to see a Godot game, the concept sounded pretty interesting.  Reminded me of those Mario challenges where they avoid all the coins, which always lead to some interesting conundrums

• It seems there's an unintended(?) infinite jump.  Which was actually quite interesting in how it added to the gameplay, though the level where it's just a tower becomes very easy with an infinite jump, the rest of the game was still a bit of a puzzle.  However short it was.
• The fact that there was no indication on number of "lives" was a bit annoying, since there were quite a few times I just randomly... died.  So adding some sort of health bar, or counter etc. could be helpful.  
• Overall the hitboxes were a bit weird, the fact everything was a rectangle was very different, and definitely lead to a bit of weirdness with collisions on platforms and coins.  It made it a bit harder to judge exactly where the player would and would not collide with stuff.
• The lack of feedback was a bit underwhelming, though I can understand it I would recommend adding some sounds or some sort of visual feedback at least on collecting a coin.  It could be cool to either go all in on the "coins are evil" part and make some sort of evil sound.  Or try and trick people with a happy general coin sound, that's just my suggestions though, it's up to you.

Overall though this games concept could lead to some interesting in depth puzzles.  And it's pretty well done, not perfect, but it has enough content to leave me wanting to see where more could go.

nice simple game, but it needs a way to see how many "lives" you have, how many more coins you have to pick