I found a free online game.  It's called Duolingo.  It's an easy game; not too taxing.  A series of simple language puzzles in the language of your choice.  Short challenges that only take a few seconds, grouped into short lessons, each only taking a few minutes.  There is scoring so you know how you're doing, and recognition for continuous streaks of correct answers.  We're separated into groups of 50 at an equal level for a week at a time, and ranking among each group is reflected in real time.  Once a week, the final ranking is reported and that group is dissolved.  A new group of 50 is formed the next time you log on.  (I was surprised at how fast a new group of 50 formed with each weekly restart so I googled how many people are using Duolingo at any one time.  The answer was an astounding 30 million!)  Success in one group advances a player to the next higher group; a powerful incentive.  Being a laggard in a group results in demotion to a lower group; a powerful incentive.  There are periodic triggers to go back and review sections you haven't seen lately.  Set your own goals, then the number of consecutive days you achieve meeting that goal is reported.  If a person waits too long during the day before they play, they'll get an email reminder that their streak is in jeopardy.  There are additional incentives like crowns, lingots, and other rewards that I don't intuitively understand because I'm not otherwise a gamer.

 

A nicely designed game; an easy diversion that has just enough interest for short bursts.  (It's not something I'd want to do for 8 hours straight, but maybe that's just me.)  It's a lot like sudoku; a simple way to sit down and zone out for 10 or 20 minutes.  Just like Sudoku, a light distraction, with the exception that over a period of time one might absorb a little bit of a different language as well.