A the 8 minute mark, as the helicopter descends into view, it has wheels, then when you see it depart, it has skids.
When the friends are standing on the roof waiting for their helicopter they all have the exact same type and color of luggage. Why would four separate groups of people have the same luggage? The propmaster clearly just bought four sets of the same thing to save time.
When Neil and his friends fly to the resort island, they pass over trees covered with colorful autumn foliage. Yet it is clear from the scanty attire worn by the people on the island, e.g. shorts and skimpy bathing suits, plus the green leaves on the trees, that the film is supposed to tale place in the summer.
One of the Characters is shown using a light bulb to burn her boyfriend, but she is using an LED bulb, which doesn't get hot.
Didn't Jason take a hit of Urge when he was leaving his meeting with "the man", the guy in the red suit gave it to him. Yet later when they are at Volcano Jason takes another dose. What happened to "you can only take it once"? Then the next day he takes a third hit.