We need a user account to store your progress: what puzzles you've completed, what code you've entered in order to save progress if you didn't complete the puzzle yet, coding streaks, etc. We're not collecting information about your device.
It's been easiest for us to do this user account creation using out-of-the-box Google Authentication, so that's why we went down this route. Hope that makes sense!
So to sum up : you’re not collecting information, you just want the user to be able to retrieve what he has already done.
First, you should ask for an account creation only when the user have already started. As I said, I didn’t even see if it was interesting at all, because of the login wall.
Second, if there are no sensitive information collected, there is no need of using a mountain to hit the nail. A pseudo will be enough. No email needed. Not sure if it even need a password...
You store the pseudo locally and you are done.
(I agree I’m a little bit oversimplifying, but you see the point)
It's been easiest for us to do this user account creation using out-of-the-box Google Authentication, so that's why we went down this route. Hope that makes sense!