Great movie, but with some major flaws

Rating: 7/10 (24 March 2017)

First of all, this was a great movie, maybe partially because i am a huge fan of this sci-fi/Thriller/Horror genre, movies like Alien, Event Horizon and Sunshine are awesome.
It did however have 3 major flaws
1.The crew seem to have no training in how to handle a security breach, they seem to just be normal people in space, acting on emotions rather than rational thought, this continues throughout the movie.
2. No matter how tough an alien life form could be from evolving on Mars, where our best Theory on Mars history is that Mars used to be allot more habitable, but slowly or maybe even rapidly declined into it current state, there is no way it would so easily be able to manage space, it is -171c and depressurised, if exposed to space for that long, it would at least just freeze solid.
3. The whole ending is made to make room for a sequel, but to what use ? the life form is not only massively overpowered and much more tough and smart than the aliens in Alien form 1979, it is an organism consisting of a complex system between trillions of independent cells, meaning every single cell can become a new big alien. Hence once they crash on earth, given how fast we saw it grow and just absorb other lifeforms and manage to survive extreme conditions, it merely needs to drop itself into the ocean, fall apart and within a day, you would have trillions of them running around after they have all grown up. A Sequel would just need to last 5 min, and its game over.