As a sci-fi fan i really liked this movie.
This film is a reminder that a good movie, even more a sci-fi isn't about the effects but the story and its characters, it's about a good plot.
Here it's obvious they would hove done a better movie if they could, they even show that to us, but so what? star wars was also a low budget movie in its time.... not that i'm comparing both, only pointing out that this isn't anything important at all.
Yes it has some flaws, but this movie does it right and well in so many ways and things (i dont want to add spoilers), and thats what makes it so good. And also
vonsidering the low budget and low resources they did a great job, and it's very entertaining. Also the movie has contains several unique ideas like the robots not having a humanoid form, but instead they are just practical, weird and very mechanical. Also they dont waste a lot of movie time talking science BS to explain the whole stuff to us, we learn what we need trough flashbacks and quick conversations. Also we have a really strong female that doesnt need to be rescued from the male, thats very atractive but not sexualized - she uses normal loose kakhi pants (not uber tight) and an ordinaty tank top - no cleavage or bum shots whatsoever - now thats awesome that they treat the female with respect.
Compared to hollywood that spends millions and has the best resources and releases abominations like battleship (more like battleshit), terminator genisys (pure garbage), Jupiter Ascending , the Green Lantern and Gods of Egypt (and many others).