I like logic puzzle games. A side effect of being mathematically inclined, I suppose. When I first found Minesweeper, I spent way too much time poking at those little squares (and often blowing myself up). If Hexcells had existed back then, I might never have stopped.
As with all really good logic puzzles, that simple idea becomes fiendishly complex. Sometimes the patterns are huge, with dozens of cells and a ton of clues. One part of the pattern might be impossible until you've unraveled a different part. Sometimes the patterns are small, but every clue is interconnected, so finding even one cell status requires deep thought.
There are actually three Hexcells games, each of which comes with a good number of patterns to unravel. As you progress, you'll be introduced to new kinds of clues and more complicated patterns to solve. In the third game, Hexcells Infinite, there is also a random-pattern mode that can be played effectively forever (thus the "infinite").
In Hexcells, you're never stuck. (Unlike some similar games where sometimes you have to guess.) You might think you're stuck, but there's always enough information to figure out at least one of the remaining unknown cell statuses. That one leads to another, and another, and eventually you have them all. Whether you're smart enough to figure that out is another question, of course.
If logic puzzle games appeal to you, pick up Hexcells. Pick up all three, for that matter. You won't be disappointed.