A Mail to the Moon

This is a game for the Game Off 2020 with the theme, Moonshot, in a month. I've been working on the game, polishing it to look good enough until now. 

You are a young boy who misses your father, an astronaut, currently residing in the moon for about 3 months for a certain project from NASA. You missed him so much you wanted to communicate with him. However, we know that cellphones won't work in space and there are no mailman who can deliver a letter to the moon. So, how do you solve this problem? YOU BUILD A ROCKET AND LAUNCH YOUR MAIL TO THE MOON!

The game is playable only with a left click of the mouse, so it's only one button.