This is more of a nice to have, but it will be really, really, really nice to have Google Play Achievements for this game. What do you think?
It might be cool (what kind of achievements are you suggesting?), but I think it's more important to add Google Play cloud save
Not urgent or critical feature, but would be nice a gamification system by number of levels solved for example: 50, 100, 200, 400.... and number of games created.
I don't think so. Google Play Games (Android) and Game Center (Apple) offer an API to define objectives and mark them as achieved or not.
Yes that is true, my bad, I meant to say it would be easy to cheat on those achievements since you can play the same levels over and over but it is no big deal. +1 here
Well, @Martin Magni can control QRs already solved, so don't increment counter if played and solved again and again.