I’ve just finished this (thanks to their free weekend!) 
I reckon it’s a nice look into Elixir and also serves as a great way to revise and practice some of the things you’ve learnt after reading Programming Elixir and/or Elixir in Action (currently the only two books I’ve read myself) or after any of the other comparable Elixir books that cover the language in detail 
It’s certainly a lot of fun having to do live challenges 
and if this is your preferred method of learning you’re definitely in for a treat! (Just keep in mind that you’ll still want to read at least one book because they generally cover the language more broadly).
