Fun idea. Here are some suggestions:
- You don't need it to confirm the cell click. That takes away from the enjoyment. Noone knows if "cell 74" is the one you meant to click or one next to it.
- don't show a popup after I click the spot. The game is quite intuitive when you see the number in the cell.
- don't start the timer until I click away the instructions.
- maybe add a gradient color from red to green depending on how close I am?
- another mode could be to include more than one spot. Then have the number only show the closest one.
