10/10
By far my favorite casual puzzle game.

Hexcells is a prime example of excellent design.
The dev has done a great job interacting with and taking feedback from the players, and shown that he cares about his work. The refined polish of this latest entry in the series makes it stand out from the masses of mediocre puzzlers on Steam.

Yes, the game is practically infinite: the generator taking a 10⁸ seed means there are 100 million challenges (actually twice that if you take in count the difficulty toggle). That's far more than could be completed in a single lifetime. Many times over, in fact.

My only gripe is that hard mode is inconsistent: some puzzles take barely a minute to solve; while easy mode is far too easy: it's so boring that clicking the tiles feels like a chore.
Fortunately, easy mode can be avoided altogether, and the occasional quick puzzle doesn't detract much from the experience.