To be fair, this game looks really cool. :) What made it so popular? About how long is it?

There's so many of them for doing basic actions and progression-wise player needs to complete only first world... What are chances you'll add some "substantial" ones? "Defeat the boss of world 2/3/4", "complete all quests", "find all artifacts", "three-star every level", "get a lot (some really high number) of total points across all levels", something like that....

Hello, I am a freelance graphic designer. I have nearly 10 years of graphic design experience. For the last 4 years, I have been working in areas such as game designs and UI. In general, I focus on game logos. As I see it, you have a very beautiful project and I am writing you this message in order to give your project a better face. If you are looking for a logo that will make you stand out, I can help you with that. If you want to see my previous designs, here is my portfolio. ; https://www.behance...

Can 3-13 be really done in 81 moves?

You can suggest some ideas for the game here! List of ideas i like: Show score of the level (Подсвечивать рекорд на уровне) Small secret in the game files (Секретик в файлах игры) Infinite mode like immortal boss or gems rush (Бесконечный режим типа бессмертного босса или Gems Rush из мобильной версии, хотя я знаю, что не стоит надеяться на это)...