A few other points on further reflection:

- If you're giving us all the factors, and all factors are necessary (e.g. to make units work out), then clicking them is a bit of a pointless activity. You could just give them as a list of sliders outright.

- The above points out that there's not much of a "gameplay loop" to speak of. We make 3-4 guesses and game over. I think this places a hard cap on how much "fun" Fermi can be. Even in something like Wordle, which is also only 5 guesses, each guess builds on feedback from the last; it's interactive and strategic.

- You could consider for instance maybe chaining multiple Fermi estimates, that build up to some bigger one. That would give you a mechanism to give intermediate feedback, and have a multi-step game.