Continuity mistake: When all the monkeys are in the kitchen, Judy and Peter open the door to peek inside, and a monkey throws a tomato at the kitchen door, making a big stain of tomato juice on the door. When the monkey throws the knives at the door though, the stain has vanished, and the door is clean. (00:25:55)
Continuity mistake: After Peter discovers the bat in the attic, he runs downstairs screaming, and you can see a chair by the door of the attic with a white cloth sitting on it. However when Aunt Nora walks upstairs, there is no sheet on the chair. (00:18:00)
Visible crew/equipment: In the scene when the pods and vines start growing all over the lounge, there is one shot of a green vine crawling towards a carpet, and then slithering under. Watch closely, near the carpet, and you can see the wire attached to, and controlling the vine, because the light shines on it, exposing it rather well for a second. (00:48:40)
Visible crew/equipment: Near the start when the young Alan goes to open the door and there is a close up of the handle you can clearly see the reflection of the camera man. (00:12:05 - 00:15:10)
Continuity mistake: When Alan confronts the lion with a knife, the blade is either facing flat or sideways depending on the angle.
Continuity mistake: After Alan traps the lion in the bedroom, it makes claw marks in the door. The marks change greatly from the first close-up of them being made, to the second shot when Alan walks away from the door. (00:28:35)
Revealing mistake: When Alan's merged with the floor and the first huge spider shows up, there's a thin wire coming out of its rear to make the animatronic move.
Continuity mistake: When the earthquake begins, the floorboards start to break in two, and Alan starts falling so Sarah holds onto him. Watch the small circular window in the wideshot. (the window that the mosquito flew out of earlier in the film) To the left of the circular window are some empty wooden beams, but no items. When it then cuts to a closeup of the window breaking in two, items have appeared on the beams, and there's a banjo hanging up etc. (01:25:30)
Revealing mistake: In the scene where Van Pelt sticks his hand out of the pile of paint cans you can see a can roll and bounce off of his extended fingers. A can of something that heavy would stop, not bounce off. Van Pelt's hand and wrist are shown covered in paint, so we know the can wasn't empty.
Continuity mistake: During the stampede, when the four are watching the animals pass by the hall, Sarah is randomly next to Alan or behind him. Also, when the stampede ends, the four swap from being separate to firmly together in a mere frame.
Continuity mistake: When Alan drops the dice, after being startled by the clock chimimng, one die reads 3, the other 2. Yet when his board piece starts to move, you can see both of the sides of the dice, both reading 2. (00:13:25)
Audio problem: When the Bat Exterminator is pointing at the book in the attic, he says "Some kid said she saw a bunch of those back in the 60's." His mouth is visible in the screen, however it doesn't move at all. (00:18:50)
Continuity mistake: In the store, Hunter Van Pelt shoots his gun and hits the side of the tyre shelf, making a nick/hole in the red paint. The size and shape of the nick/hole changes between the two closeups of it, before the chain snaps and releases the tyres. (01:09:25)
Continuity mistake: During the scene when Alan is trapped in the quicksand, and the others are giving him items to hold onto, you can see behind him, to the viewers right of the blue chair in the background, a small stack of newspapers. But in later shots, such as after Peter runs out of the attic to go to the shed, and we then see Judy crawl over and grab the wooden music stand, to hit the spiders, the stack of newpapers has vanished, and a few other items change position, like the tennis racket. (01:20:55 - 01:23:00)
Continuity mistake: As Mrs. Thomas is being taken from her car, after being bitten by the mosquito, the men put her on a pedestal and you can see she is wearing long green boots that nearly reach up to her knees. Yet when they are putting her into the ambulance, she has black heeled shoes on. (00:37:50)
Continuity mistake: In the attic, Peter takes the Jumanji pieces out of the compartment, then closes it. Then when he takes the dice out the compartment, the compartment lid is open, not closed, and no-one touched it. (00:24:00)
Continuity mistake: After Sarah and Alan have been embedded into the floor by the quicksand, she rolls the dice with her teeth onto the board that's been propped up on Alan's face. The next time we see the board, when Peter's fighting with the spiders, the board's completely flat on the floor, when Alan's head should be propping it up. There's no angle between the main board and the two halves that fold out, but they are bent downward in the previous shot. Also, after Alan moves the board, at first it's relatively perpendicular to his face. Then, a few shots later when the spiders are retreating because of the impending earthquake, the board's rotated 45 degrees and moved farther away. It wasn't moved by rumblings from the earthquake- this is before the ground actually begins to shake. (01:28:15)
Continuity mistake: When the pelican grabs the game, there's a wide shot of Alan running behind the bird. The damage on the side of the arch behind is bigger than it was in the immediate previous shot.
Audio problem: When Van Pelt is chasing Alan outside the house, he turns to shoot at Carl the cop. If you count the shots heard fired, there is one more hole than bullets heard. (00:56:15)
Continuity mistake: When the monkeys go into the police car, they take the shotgun and fire it through the roof destroying the roof lights, but in all the later shots of the car the lights are still destroyed, but the roof shows no damage.
Answer: The game is essentially "resetting reality" back to the point Alan was first sucked into the game. So it is undoing everything that has been done - including taking away the gun and bullets Van Pelt had purchased.