This is a version of the classic strategy game of “Mine Sweeper” with emoji faces instead of bombs.
A classic game, similar to Mine Sweeper, MindField has you hunting for happy-face mines. You must find them not by clicking them (oh no, that would blow you up!) but instead you find all clear areas around them.
Squares with numbers are hints that tell you how many adjacent mines there are (either to the left, right, top or below the square with the number). So for example, a square with a 2 on it has a mine adjacent to two sides of it. The question is, where exactly are they?
If you are pretty sure where a mine is located, you can mark that square with a flag (and get points for it) by holding the CTRL key while clicking the square.