The third and most likely final sibling in the Hexcells family, Hexcells Infinite, like its title suggests, provides an infinite game experience: in addition to another set of 36 hand-crafted levels, it includes a random puzzle generator!
The hand-crafter levels are about as difficult as the ones in Hexcells Plus, or marginally easier (either that, or I'm just getting better at solving them.) I regret that only one of them provides special instructions (in this case "each column contains an odd number of blue cells") as I feel more of them would benefit the challenge variety. This absence is also partially responsible for the scarcity of satisfying "aha" moments, when several clues combine beautifully into a challenging part of the solution. Previous games had me complaining about the puzzles' less than perfect elegance: you usually have quite more clues than you really need. This is still a problem, even if it's now marginally less severe than it was. Another issue, especially for newcomers, is that nowhere in the instructions does the game direct your attention to the box at the top left corner, containing the number of yet undiscovered blue cells, even though it's an essential information for many of the puzzles. All of that didn't stop me from enjoying the 36 puzzles and feeling a real satisfaction each time I could perfect one. They are more missed opportunities than mortal sins.
The real attraction of Hexcelles Infinite, of course, is the randomly generated levels. There are 100 millions of them, so there is no risk of running out before growing completely tired of Hexcells. You can let the computer choose or you can specify a seed yourself, so it's easy to share a level with your friends . There is an option to use the date as a seed as well, and have a "puzzle of the day", but don't expect a leaderboard for it, à la Spelunky. The real question is this: "Are the randomly-generated puzzles as good as the hand-crafted one?" Predictably, the answer is no. Mainly because the elegance issue, that I mentioned above, is considerably worse. Random levels are chock-full of redundant clues, and lack any kind of the symmetry that makes a puzzle attractive. I find that a real shame, as it shouldn't be too difficult to devise an algorithm that gets rid of some of the redundancy, and maybe couple it with a difficulty setting. Are the random puzzles good enough to sustain interest? Your mileage may vary, depending on whether you play casually, or seriously. "Serious" players will lament the low difficulty. Most of them took me less than 4 minutes and I've yet to find one that I couldn't solve in less than 10. But that may be exactly what you're looking for, and as a way to relax and pass a bit of time, the random puzzle generator is serviceable. Nevertheless, my impression is that those that enjoy the kind of challenge offered by the 36 main levels, will find the random ones too trivial for their taste.
Audio-visually, Hexcells Infinite is identical to its predecessors. You get the same white, blue and yellow colours, the same menu presentation, the same ambient soundscapes... It's all very nice and stylish, but a bit of variety, like selectable visual themes, for example, would have been welcome.
Hexcells Infinite is the best Hexcells yet. It feature another 36 good, difficult puzzles and the random number generator has the potential to satisfy your need for casual puzzle solving during a great many hours.