I think I found a bug, when you get to Vx 100 and Vy 100 then there is a chance that the game will shoot you in the other direction without you pressing anything,Vx -100 Vy -100.
I added a sort-of barrier to the edges (at 1000 or -1000 x and y) that accelerates you in the opposite direction to keep you from going to far, where nothing is generated.
It might be different, but I think that you may have simply exceeded 1000 or -1000 (x or y) and the game pushed you in the opposite direction.
Now you can press (the key) C to launch a missile! The missile only goes in one direction, has a longer cool-down time, and doesn’t home in on anything, but it does more damage and it goes faster than the regular projectile.