This is either brilliantly written or badly written. I don't know because I don't know what the writers were intending. If this is a brilliant horror film with a hidden monster and a strong counter culture message, it deserves a five for having guts to carry it's message so quietly and so well. If this is actually a case of plot holes and bad writing with socially accepted traditions meant to paint in the rest of the character, it's worth a two for being lazy and relying on socially accepted clichés. I'm giving it a 3.5 (rounded to 4) to be safe. Overall it was worth the watch but I don't think I'd rewatch it any time soon.
Why do I say this might be a counter-culture messaged horror film? Spoilers ahead.
We are supposed to feel sympathetic for Craig because he has a wife and kid and is going to be evicted. When you are going to be evicted you have to miss rent for multiple months, be given multiple "you are late, please pay" warnings, and then you are given an eviction notice. He shouldn't have been shocked to see the eviction notice on his door. Also, how does the wife NOT know about the money problems? How poor is his relationship with his super important family that he couldn't have a talk about their spending habits? If things are this bad certainly there are other bills not being paid. That means lots of collection notices. Working as a mechanic is good money. He lives in a small apartment in a cheap neighborhood. How did he end up so far in the rear? Also, mechanics are always desirable. Finding more work should have been easy. Put it all together and you get a neglectful prideful/fearful man who lies to his family constantly, probably as a selfish attempt to save face at his failed writing career. This is NOT the behavior of a responsible, loving father and husband. It's a simmering monster.
And then we have Vince the sex-maniac dropout who has done nothing with his life supposedly. Wait, if that's true, why is he the one with a stable place to sleep, money, and a job? Ok, so he went to jail once, but he has been on the right side of the law since then. It's not like we haven't heard of anyone ever making a mistake then trying to get better. When we first see Vince he offers Craig a few hundred bucks to try to help him. He worked hard at menial jobs that pay way less than a mechanic makes to get that money. People won't give him better jobs because he has a criminal record. Vince even says so. A few hundred bucks is a week's pay for him. He doesn't care, he wants to help. When he finds out this won't help, he is sad. He encourages Craig to do things because he wants to help Craig feel better any way he can, even if that means goading him to have some drinks and to play the couple's game for awhile. Vince can be competitive even to the point of playing dirty, but outside of that he doesn't appear to be a selfish or cruel man. He even apologizes for most of the things he ends up doing to Craig. This is not a monster. It's a man who makes mistakes.
He and Craig supposedly were alike in high school except for the fact that Vince was always standing up for Craig because Craig was too scared to stand up for himself. What happened? Vince didn't get married or have kids. He chose not to follow the status quo of "get a woman, get a job, get a baby, die" that society forces on people. Without those extra responsibilities tossed on him he could think clearly and realised when things went too far. Craig was willing to lose the last shreds of his humanity in order to maintain the socially approved way of living. Vince wasn't. This message is about as counter culture as you can get.
If this message was the writer's intention, kudos for being bold enough to buck the standard "babies and families are always good and all good people have them" cliché. If the lack of research into what would lead to Craig's situation plus the cliché excuse that being a parent somehow makes everything he does OK as it's "for the family" actually turned what was supposed to be a hero into a monster, then this movie sucks. As to which it is, unless the creators straight up say then I wouldn't know. Watch it if it interests you. That's all I can say.