Teckstack: Quiz-Based Learning

Hi all, I've been working on this site called Teckstack (https://www.teckstack.net/) that offers quiz-based learning and knowledge evaluation. Currently I've got a handful of questions in JavaScript and React and a few features.

Let me know your thoughts, should I go deeper or broader with content, add features, etc?

Sorry in advance if the site marks any of your correct answers incorrectly! Still a WIP but looking to improve.