Thanks a lot for your feedback, the artwork was indeed made by us yes, and it's probably the only thing we're proud of in this game. We  planned on adding stuff like music but in the end we couldn't work as long as we wanted to because both of us had other stuff to do. And yes there are still a lot of bugs in the game and the value of the cystals going below 0 is defenetly not the only one. But we're working on fixing them and adding more and more stuff untill we get the game to look like our first vison which was a Survivalgame with 2 worlds in which you can find different resources and you have to trade them between the worlds to craft certain Items, while avoiding enemies and the constant rain of Meteors.