Nice puzzle game concept. Holding space and pressing a number to fill a space felt a bit unusual; maybe using the arrow keys to navigate the spaces would have been a simpler control scheme. Since it's not possible to modify a space after you've filled it, I think it would be good to check the rules each time you fill a space and cause "game over" (or a reset) immediately when any rule is broken, because after one wrong move anything else you do afterward is just a waste of time. I think it might be nice to have a button to count the total number of ones or zeros (or announce the initial counts at the start of the level), because this is the part for which it is not enough to just look locally around the place you want to fill. The long explanatory text repeated for each level also felt like a bit much, but it was possible to interrupt it.