This game is really fun, well done! The character designs are adorable and the movement feels really smooth. Pushing the various quarks around is a nice mechanic and it works really well. They all have something fun to say too.
I managed to complete the game after a bit of trial and error, but I got the "sub optimal" end because I couldn't stop myself from shooting the little star quark that told me how to shoot things. I had a lot of fun with it though. The soundtrack suits it well too. My one suggestion would be making some sort of quest tracker, so that the player can see how many quarks they still need to bring together, and how many to destroy. Otherwise, players might be left wondering the map for a good while before they figure out what to do next.
If you don't mind, I would really appreciate it if you could check my game out as well :)