Where can I find Codecademy for Written Chinese?
To memorize characters and pronunciation you can use Memrise, which will help you to learn by repeating words you've missed during the previous learning session.

However, you won't learn any grammar or usage, just words. So it is not a complete solution, but a good help to expand your vocabulary.

It is not as feature complete as Codeacademy but I don't think that what you are looking for exists (yet).

If I were you, I would keep an eye on Duolinguo, which does not yet provide Mandarin but should in the future.