Great reproduction of a great game, I like a lot the addition of being able to reverse instead of having to rotate the ship and go forward, it makes the gameplay more fluid. Also big rocks taking more than one hit now makes sense.
The only slight issue is the lack of cooldown on the firing making me destroy my hand and keyboard to transrform the ship into a vulkan gun. Also maybe I was too bad at the game but I didn't see the little flying saucer are they in the game ? If not, I would definitely like to play a version with them !
Nice work !