Sometimes, when there is a little free time and nothing really important will get done, it feels like that time will be wasted, even though actually it is exactly the kind of time we often forget about. Those little bits of time can be a great opportunity to rest a bit and catch your breath. Generally, in moments like that, I prefer something simple and straightforward, for example https://magicpuzzles.net/ , where I do not have to pay for the game, I do not have to figure out how everything works, and when it comes to assembling puzzles, everyone knows exactly what to do.