Most RPGs nowadays have an autosave feature of some kind or another; therefore, I have been desensitized to saving. You should at least let us know that you do not have one, if not create one.
It is difficult for me to strategize the interaction between mirrors when I am not certain which directions they will be able to face. I would definitely recommend making that more clear from the getgo.
It's a nice game, I enjoyed it. I understand the heavy drift is part of the challenge of the game, but the weak thrusters just seem to make the game go slower. I would say crank up the thrusters a little bit.