I really like the concept of your game, but I did find a crash bug (that is generally impossible to reach). I wanted to find out what happens when you reach level 100+ (since 100 numbers is the maximum for a 10x10 grid). With any level past 100 the game will instant crash when trying to generate the numbers in the grid, so you might want to put a check in for that.

If anyone cares, I used CheatEngine to reach level 100+