Acceleration is very high, so that the ship can reach maximum speed quicker, making it more responsive, but yeah, it seems like it makes the movement more jerky, instead.
Rotation is purely cosmetic, controls are not relative to it, ship is always turned in the same direction its velocity vector points to.
There are gonna be more enemy times, right now only two are implemented.
Anyway, thanks for the comment, I'll check your game later.