It was definitely tense, but overall pretty shallow. Oh no, the mysterious alien turned out to be hostile, and everything is going wrong, and it's so foreign that nothing can kill it!
If you're into sci-fi tragedies however you'll probably enjoy it more than I did.
The beginning was lovely but it made me irrationally angry when you realize that it was all for nothing other than a couple details on what the plot is GOING to be, that had absolutely no bearing on the plot.
Also, just because you added a plot twist, doesn't mean it wasn't predictable. I actually would have preferred it if they didn't add the twist, instead maybe adding more genuine emotion into the scenes leading up to the last big thing for more of an impact. I don't know, maybe I'm just watching the wrong genre.