AirSabe’s review published on Letterboxd:
A solid, "survive in space" type movie that was interesting to go into blind. I could infer from the title that there would be an unwanted passenger of some kind but I had no idea if an alien was going to pop up or what the stowaway's motivations might be. There is a nice little mystery in the first act where the movie could have easily shifted into horror, science fiction or a thriller. But as the trailer divulges (so I will divulge too), this quickly settles into being a psychological drama and story of survival centered around a classic moral dilemma. The characters are all well-acted and given just enough backstory to make us interested in how they will hash out the this gut-wrenching scenario. Reading the online chatter after watching made me aware of a slew of technical problems with the science, but while watching, I didn't notice most of them and I was able to overlook the ones I did notice for the sake of the story.
However, the film starts to feel a bit lackluster the further it goes along. The most compelling part was how an unsuspecting passenger would have to adapt to the fact that they have to be on this space mission for 5 years but we quickly move into more of a pure, survival story. The finale centers around a spacewalk that just didn't hook me as much as it should have. Maybe it's because this film starts to enter very familiar territory without doing anything new. Maybe it's because it goes for huge emotions that I wasn't at the level of emotional involvement for it to pay off. Or maybe I have seen so much spectacular imagery in films like Gravity that it felt a bit tame and slow in comparison. Whatever it is, Stowaway ended up being a movie I was always interested in (I almost always enjoy space movies about survival that are competently made) but not one that I was ever fully compelled by.