I thought the overall plot was enjoyable and very suspenseful. I will say, as a rule of thumb for a film like this, do not make your characters hopelessly stupid. Sure, people do stupid things when they’re scared, but this was very extreme. The more stupid your protagonists are the less I want to root for them. Think Cloverfield lane as an example of a scared but thinking character. Also, there was no clear main character. At the end I was not happy for any potential main characters.