(May contain spoilers)
I enjoyed this movie very much, and people say the ending was bad but I loved it. It made me think, "what could possibly happen next?" or "Where is Mackey now?
I have like the best idea for the sequel. It could be called "Summer of 85" and like in the beginning we could see Davey, Eats, and Curtis attending Woody's funeral. But Curtis and Eats could be like distant from Davey, because they probably blame him for Woody's death and getting them caught up into this mess. Davey probably still has traumatic flashbacks when he witnessed Woody getting killed. Eats, Curtis, and Davey probably kinda faded away since then. Then like a year later passes and probaly in one of the scenes and Davey is taking out the trash, and Mackey appears behind him and says "I told you I would be back". Then maybe Davey, Curtis, and Eats get kidnapped and they get reunited again.