Idle games have carved out a nice niche in the mobile market, not surprising as many of us just want a simple game to pass the time and amuse ourselves. One of the better ones is Happy Glass by Lion Studios . The premise is simple, draw a line to pour water into the glass to make it happy. It is basic enough in the beginning, but you will want to keep playing.
All you need to do is use the pencil tool to draw a line so when the water pours, it goes into the glass, filling it up. Once filled up the level is complete you move on to the next level. At the early levels, it is as simple as drawing a short line, and this is good as it gives you a feel for the game.
The challenge comes later on as you need to draw more complex lines to ensure the water gets in the glass. Moreover, you have to make certain the glass does not tip over. As you progress it is going to take more than just a straight line. You will need to draw under the glass and be more creative. Since the levels are progressively designed the challenges feel fair.
Completing the level earns you stars, and the less ink you use the more stars you get. So the purpose of Happy Glass is not just to fill it up with water but to use the least amount of ink possible. In other words, it is an intellectually challenging and fun game.