It took me one round to figure out how the game works - Personally, the description for the 'How to play' didn't really help me understand it but that didn't stop me from playing.
This is a very enjoyable game and I found myself loving it.
I like that I can take my time and figure things out. Since the timer on the side just tells me how long it took me to finish it, rather than how much time I have to complete it, there is a lot less pressure. Which I like, since I hate feeling pressured to finish and it helps me to know if I was able to finish it faster the second time around, than I was on the first try. Which I did. And I was proud of myself.
All you have to do is look at the numbers carefully and think them through. Its a fun game and I'd recommend it to people who like puzzles.