I think this game has a TON of potential, the art style is nice and unique and there are some nice mechanics implemented. But, doing the conveyor belt stuff just freezes the game, and the secret ending (?) doesn't feel like an ending/doesn't actually end the game.
I had to look at the source code (super cool for you too upload this) to see if it was broken but it just stops after adding items to the conveyor belt, and completing the secret ending (?) doesn't really seem to end the game (unless I am missing something, not particularly familiar with godot).
I think the game just needs an ending in some way - though I think what you have done is great for the 5 days :)