Maybe it's just my personal preference but I feel the aliens of 1 is a lot cooler than the one in 2. 1 also gives kind of hang at the end but I feel 2 concludes it a bit too quickly. Again just my preference. Don't know the right word for it, but I like when an idea is not presented clearly to the audience, for example in 1 the aliens are essentially lovecraftian, we have a lot of questions unanswered. I feel 2 answers these questions too clearly.