Eyyy, I got the secret ending :D !!!! Damn is this game challenging, kinda out of place for a game jam, considering that most people will give up or just complete the regular 15 levels (which is still a loooooot btw).
I honestly didn't like some of the levels and I felt like my solution are overly complicated. The one that took me the longest time is level 10 alternative solution, where I had to put in a pen and paper to find where to put the numbers in the first place. My favorites are 13,14,15 alternative solution, they are short and sweet and clever I must say. The raft hints strikes a good balance, between being confused when you first read them and understanding them once you look again at the levels. I first thought that multiplication node was unnecessary complexity but really it made things much more interesting by basically "storing" the values until the next signal.
I wonder if yall played inscription because I LOVE that game's vibes, and yours provokes the same feelings as well.
I think it lacks some polish like sound effects, better dialogue or a simple tween bounce animation when clicking on a node (you could do that in 2 lines of code in godot lol). if time was spent on that instead of making so many levels, the game would be so much more elevated, always go for quality over quantity! And also improve your tutorial because first level is too hard heh.