2D Space Shooter thingy - (Not) my first game

Your objective is to destroy all the incoming asteroids. They come in waves, each wave being separated from the next by a few seconds. You start the game with 3 Hit Points (HP), every collision with an asteroid will take you 1 HP (no matter its size), and if your HP reaches 0 it’s game over. Destroying asteroids will earn you points, and you’ll lose some for each asteroids that reaches the bo…