Completed both standard and expert modes with no hints used. Well, this was quite the time-sink! With over 500 puzzles to solve, Konami's Pixel Puzzle Collection will last even the most dedicated picross fan a long time. There's a nice range of difficulty, ramping up well as you solve more puzzles - until you've solved each puzzle, you can't choose which come up, with them instead being presented to you in a somewhat 'random' order, other than easier/smaller puzzles generally coming first - and the game neatly avoids the potential for frustration that could arise if coming up against a particularly tricky puzzle by offering three 'slots' for puzzles to be attempted with progress saved, plus an additional one for multi-part 'boss' puzzles.

The touch interface is well-designed for the mobile format; beyond that, if you enjoy picross, or logic puzzles generally, you can be sure that you'll have a good time here. Once you've solved each of the puzzles once, an 'expert' mode opens up - this features exactly the same puzzles (plus a handful of additions), but the key difference is that you lose the functionality allowing cells to be marked as blank. The added challenge here is more one of memorisation/visualisation and far from essential, though it's a decent enough way of extending the playtime if you're dedicated and don't find it too frustrating.

Overall, this is one of the best mobile picross games that I've come across of late, very much recommended.