This was a good movie, for what it is. They obviously invested lots of energy and money into the FX, and the space scenes are beautiful and plenty. Judging by the trailer, I honestly thought this movie was going to be dull. But after watching it, I was amazed by the effort put into it.
This movie, however, is only going to be worthwhile for the beautiful and plentiful space scenes and not so much the plot. Without revealing too much, the whole effort of the main plot was essentially rendered useless by the end of the movie, essentially canceling out the entire purpose of the main character and half of the plot line development. The protagonist had no real effort/effect in the end, making you question why they didn't just merely put an antagonist instead.
There are too many reviewer snobs who try and correlate all the wrongdoings of the movie with reality and physics, but fail to understand the definition of entertainment and fiction. Don't listen to the advice of these types of people, they will always be miserable, judgemental, and criticizing while never achieving anything noteworthy of themselves worth critiquing.