It's a pretty fun game that makes me think of 2048, and I think it would be a good educational game for children to practice their math skills. Although at first I thought it might be more satisfying to be able to do the calculations by draging the numbers with a mouse, I think using wasd can actually force me to plan a little bit and try to do the calculation with the minimum steps/shortest route to minimise the time I use, which adds an extra layer of fun to the game :D

A funny time-killing mini game. I would like to keep playing it when waiting for a bus/taking the train if it is a mobile game.

It is quite fun to play. I have a lot of friends and family members that are not gamers and will have difficulty understanding most game mechanics. But because maths is something most people can understand, I feel like this is a game I can play with a complete non-gamer. My only advice would be to make the numbers easier to read. Eventhough you used different shades of green for different colors, it is still very hard to identify them. Similarly, plus and divide should have different colors as their symbols are already very similar.

Gotta admit genAI has done a good job here. But I hope you would some day recreate this yourself with your own code! Because then you'd be able to develop this much further into something that genAI wouldn't be able to do. Good luck!