I really like the game mechanic and the idea behind this. It's very cool to see Minetest games that aren't just your classic survival sandboxes
Just I was starting to enjoy it, it ended though :(
I think it would be good to see sound effects and music, more levels, and perhaps improvements to the player movement (it felt a big choppy and weird to use, although, I suspect you'll be limited by Minetest in this). Another thing that might be useful would be to add a prompt to the first level like "Push boxes into the orbs!"