It's a good starting point, but clearly very early. The "Random challenge" shows a lot of promise, since it brings a lot of the more sokoban thinking about spacing and plotting a path forward. There's room for more levels which mix up the challenge, between the arithmetic puzzle, the sokoban style path planning and the the operators which throw a wrench in both.
On a practical note, I'm unsure if it's possible to go back to the main menu, the popup says you can but backspace seems to put me in edit mode, and I don't think the leaderboard is working correctly on web (it couldn't scroll down) though I might have been missing something.
Hope you explore this more!