50/50 puzzles solves; 100% of achievements. Not as superb as the HexCells trilogy, but this is another solid puzzle game from Matthew Brown. The game is somewhat more reliant on maths/mental arithmetic that I typically like in puzzle games, which is worth bearing in mind if you're considering a purchase. However, after this feeling peaking around halfway through the puzzles, I found this then gradually to become less of an issue as I become more adept at spotting the key patterns that allow progress to be made, without as much trial-and-error of potential scenarios.