Since you are done with your trial (Not sure as to what that means? I will note that I do not code I am just a player lol) I suggest that when you get the opportunity to go back into the dynamics of the game, that you should allow speed control be another set of commands (like F for faster and S to slow down) and then add a pause command with the letter P. From there, I would also suggest that you look into why people will blow up when the ship they destroyed isnt there anymore. I would also suggest that when you get the chance, you extend the blast radious and/or speed of the gun that your shop has so that you can make it a little easier to defend the ship when moving at faster speeds :)
Hope this helps and good luck when you get the chance to remake the game for errors and improvements! Keep at it!
 "NOT_SH00T..."){kind=icon}