A huge thanks for your detailed feedbacks and video.
Yeah, not only I should have a "control reminder" instead of a long intro (to be suuuure the player wouldn't be lost even if they didn't read the game's page).
But also I should have given more "sense" to level's objectives, like your proposal for the rings and their height in this game.
I was just a bit too taken by the idea of making the aesthetic I want... plus the fact I had prioritized the "visual mood" in the three hours I had :' D. I'll balance that a bit more next time.
Thank you again !