Saw one of the fastest turnarounds from filming to theatrical release for a major studio film. Filming did not begin until February 2019 and wrapped four months later in May, for a December release only seven months later. Most films complete filming nearly a year before their release.

Jack Black referred to this movie as Jumanji 4, citing Jumanji (1995), Zathura: A Space Adventure (2005) and Jumanji: Welcome to the Jungle (2017) as the other films in the series.

During filming, Jack Black was running a behind-the-scenes vlog for his "Jablinski Games" YouTube channel.

A brief musical leitmotif sounding strikingly similar to the main theme from Lawrence of Arabia (1962) plays during the desert sequence. This is likely a fitting homage to the similar landscapes and the adventurous spirit both films share.

The first time we see Bethany in the previous film she's taking a selfie. In this film, the first time we see her she's taking a photo, but not of herself.

Continuity

When Fridge (as Professor Shelly Oberon) jumps to the last floating bridge, he twists his right ankle and is shown limping with his right leg while he is on land. Yet, later on, when Spencer (as Ming Fleetfoot) is tending to Fridge's injury, he is wrapping Fridge's left ankle.

In "Jumanji: Welcome to the Jungle", Alex returns home to 1996, the year he was sucked into the game; 20 years before the others. In "The Next Level", Bethany and Alex are sucked into the game several hours after Fridge, Martha, Grandpa Eddie, and Milo. However when they all return, everyone is returned at the same time.

Ruby Roundhouse (Karen Gillan) is the first to fall from the airplane, followed by Bravestone and Finbar, then Shelly Oberon (Jack Black) is the last to fall. However, after Shelly Oberon stands up, Ruby Roundhouse is beyond him and walks past him on the way back to the others.

In the bar, one of the throwing axes hit dead center bulls eye. On the very next view, none of the axes on the board are at bulls eye.

Eddie's eyeglass frames change from black rimmed in the kitchen, to rimless when he goes to bed, then back to black rimmed the following morning.



Factual errors

Pretty much all of the instructions Oberon gives at the bridges are just random utterances of geometry terms, not accurate descriptions of the bridge configurations.

Bethany and Alex meet the other's and should both still have 3 lives. But after the body change when they start the last mission, Bethany (professor Oberon) has only one life while Alex has 3.

Shortly after entering the game, a plane flies overhead of the players and frightens everyone. Ruby Roundhouse (Martha) yells to the others to follow her and she chases after the plane. She would have no idea whether the pilot was a friend or an enemy to them.



Incorrectly regarded as goofs

"Once the Spencer was shown studying in the New York University the sign shows New York Vniversity - the spelling of the university were wrong." In fact, the shot of NYU is the actual entrance to the Kaufman Management Center of Stern Business School at NYU. The use of the letter 'V' in place of 'U' is common in older buildings --- particularly those in a Greco-Roman style --- following the tradition that there was no 'U' in the Latin alphabet until the 16th century, so 'V' was used to stand for both sounds.



Revealing mistakes

When Spencer is carrying his suitcase while walking in the snow in New York, it's so heavy that he can barely carry it. When he arrives at his Mom's house, however, he has no problem carrying it at all, as it's clearly empty.



Miscellaneous

Martha's cafe states 24 hr cafe on store front, however why it has open/closed sign in window. It never says closed any particular day, only open breakfast lunch and dinner.



Plot holes

Grandpa Eddie and Milo were not in the basement when the game malfunctioned and no explanation is ever given how they ended up in the game, which makes their presence confusing and unbelievable.

When Milo and Eddie are discussing Spencer, as Ming, Eddie says that Ming isn't his grandson as Spencer is a boy and Ming isn't. Milo responds by squinting and asking if Spencer has changed his hair. Up until this point, Milo and Eddie have been estranged for many years and Spencer has been away at college. Milo would have no idea what Spencer's hair was like in the first place. This is borne out by the earlier scene where Eddie barely even recognized Fridge.



Character error

In the desert, Mouse (Milo) mispronounces the Australian native flightless bird Emu as e-MOO. As a zoologist he would know the correct pronunciation is e-MEW.

When Ming/Spencer opens the padlock she/he simply inserts the tools and moves them slightly up and down and it opens. This is not how this kind of lock (lever padlock) is picked. Rather, a pick inserted into the lock is used to move the levers out of the way, thus allowing a tension wrench to turn (usually about 1/4-1/2 turn) and move the bolt, releasing the shackle and opening the lock. However, no turning motion is shown at all here.

When everyone puts their hands together before entering the castle, Oberon does the "be aggressive" chant. However, he says "be aggressive, be, be aggressive". It's supposed to be "be aggressive, b-e aggressive", spelling out the word "be" - not repeating it.