I would love to play the game but i have 0 idea how it works :( and in the menu i could not go back from the armory or in the game menu i could also not go back to the menu to find out how to play the game. 

If you know the controls or game mechanics I'm sure its easy to understand since it looks nice clean and basic. It would really help to have the control's on the screen at-leased in the start + a short introduction of what you have to do. Saying all of this i also know my game is a bit vague too :P there is a short basic tutorial with text in it. But I'm sure some people also are not going to have a clue :P

I do love the music and the pixel galaxy background looks really cool!