I've used Duolingo for about a year and they definitely have a lot of stuff like that built into the gamification. Often times, though, playing the game they designed is counterproductive. I've broken 100+ day streaks twice now because I realized I was only putting in the minimum for the sake of the game. I've found it better to take a month off here and there so that I can come back and focus on my actual goals.
There's also the cracked lesson feature. They aligned cracked lessons to urgency gamification instead of something more sound like delayed repetition. As a result, you'll often have cracked lessons which you've long since permanently committed to memory and will be spending 15 minutes on easy lessons rather than doing the important, harder lessons.
There's also the cracked lesson feature. They aligned cracked lessons to urgency gamification instead of something more sound like delayed repetition. As a result, you'll often have cracked lessons which you've long since permanently committed to memory and will be spending 15 minutes on easy lessons rather than doing the important, harder lessons.