I watched this on a whim one evening, and while the low budget, (apparently only $100,000!), was evident throughout, what the makers of this film managed to do with it was extremely impressive.
The sound design, cinematography, and direction are excellent. I have seen many films with budgets 400 times what this one had look and sound worse.
There is no useless exposition, no quasi-philosophical nonsense, and no useless technobabble. There are just enough familiar sci-fi tropes to firmly establish it in the genre, but nothing more.
The space ships, the laser guns, and the aliens are merely the backdrop for the simple, but viscerally and brutally told story of a soldier stranded in a hostile environment trying to survive and get home.
Even if you tend not to like sci-fi, give this one a watch if you're in the mood for something different.