This is a nice catch and a great hunt for people who want to learn.
See my personal reviews below :

Pros :

• It is a good website where you can learn easily learn something new
• It offers a lot of different subjects that each of us are eager to select from
• You can even play and study offline which is a good way to stay learning anywhere you like
• It can be a great source of improvement to your self as a learner
• It has many classifications of level of learning which can be an easy learning stage from people who just begun and people who are already into it
• Can really improved your oral languages and help you learn other languages as well
• This is one of a kind website and that it should be supported

Cons :

• A good source of education. I have nothing against it.