So far the game play you have established is a good start. One suggestion is having the rockets fire more often when the player gets farther in the game, it would make the game more challenging and refreshing. I can see this being a good game for a mobile device. Good Work!
This is great, especially for a game made in a few hours. If you just made the gaps get gradually smaller, it would be a lot more fun because of the added challenge. I like the idea of having lasers come at you from behind. I also like that even though you have an ancient technology connection in your story, it's funny how it seems like the game's theme is the opposite, like a futuristic space ship chase. I think it would be fun if more games purposely did the opposite of the theme.