My favorite are escape the room games. They are filled with puzzles that you must solve to escape the room. It sounds simple enough, but after you've played one you learn to approach problems differently, and that carrying a knife or screw driver might come in handy.
By far my favorite game designer is TESSHI-e from Mild Escape. A Japanese designer that comes out with a new game every few weeks. Only their games are not only delightful with puzzles that force you to solve clues, but also to build or cook things.
They are the best way I know to pass fifteen to twenty minutes. They are translated into English from Japanese. The best part of a Mild Escape game are the graphics. Each time I find myself wishing that I were really in that room. I wouldn't mind being trapped in these rooms. They are point and click games and easily navigated. There can be math involved but nothing too complicated. Plus you can save the game and come back later.
The plots may require a bit of suspension of belief. As the intro tells you that someone you know has locked you into a room, yet again. But, the fun part is getting out again.
Mild Escape has just come out with their newest game, which is a remake of their very first game. Each time a new room with new puzzles. With a total of 70 games and counting, this is one website I keep tabs on.
Mild Escape has one things that other escape the room games do not have. A secret ending. Almost all of their games have a bonus puzzle. You figure out the way to escape thus unlocking an extra puzzle which wins you the Happy Coin and an even better reward.
It may seem a bit cheesy, but I do believe that the Happy Coin will bring happiness to me.
The puzzle formats can be repetitive but the solutions are always different. The music is usually quite soothing as well. So, if you're looking for a quick break at work, or something to get your brain cells churning you should try a Mild Escape game.
Mild Escape is popular among online game players. Which has sparked other game designers to copy their styles as well as their signature Happy Coin. They are still entertaining, but they can't quite hold a candle to Mild Escape.
If you're new to the the escape room games, then you can check out escapegames24.com. Their community provide walkthroughs and tips for games when you get stuck. Also you can find many other games there as well.