This game wasn't that hard for me in most of these levels. Usually, it takes about a few seconds to a few minutes for me to solve one. I'm not a fan of difficult logic puzzles, so this is a good game to play, especially if you're a kid interested in logic games and brain teasers.
I am stubborn, and I don't usually look up a walkthrough unless I'm really stuck on a level. On level 19, I had no idea what to do for the longest time, and I had given up. Now, a year and a half later, I decided to look it up, and I was frustrated with myself for not realizing the solution sooner. I also had to look up level 22 as well.