1. Use W, A, S, D to control the spaceship and press Space to shoot。                     2. The initial fuel value is 15, decreasing by 1 point per second. The game ends when the fuel reaches 0。                     3. Touching fallen fuel bottles increases the fuel by 15 points, with a maximum value of 30 points。                     4. Hitting enemy spaceships earns 5 points。Planets need to be hit twice to earn 10 points。Hitting friendly ships deducts 10 points。                     5. Colliding with enemies loses 15 points of fuel，and colliding with friendly ships deducts 10 points。                     6. Negative scores are allowed。                     7. Press P to pause the game and M to mute。                     Start your interstellar battle！