This might be the least polished nonogram game I've ever played. The controls are kind of clunky and there are parts that feel unfinished. I don't recall any major issues with the black & white puzzles, but as you progress in the higher level color puzzles things get quite frustrating. Lots of puzzles use multiple different shades of the same color that I could not distinguish, so it just became a guessing game as to which color to use. I got it for free as part of a No Gravity Games promotion, and I'm really glad I didn't spend money on this.