Big-Lipped Alligator Moment: Jacob is running to find his companions. Suddenly he is dancing with a girl and asking if he can text her. The girl is never seen or mentioned again. However, she does show up in a deleted scene, in which she asks Jacob about his snowboard.
Harsher in Hindsight: Adam's quote: "One little change has a ripple effect and it affects everything else. Like a butterfly floats its wings and Tokyo explodes or there's a tsunami, in like, you know, somewhere". (The earthquake and tsunami that destroyed the Fukushima nuclear plant was the year after this film came out.)
Blaine is a boorish EaglelandJerk Jock who is always freaking out about how the protagonists are secret Russian spies in their midst. Fast forward to Captain America: The Winter Soldier, where that's exactly what he is (or so it seems). And yes, you did just see that guy from The Daily Show beat the ever-loving shit out of the Winter Soldier. This is only made even more hilairious when Avengers: Endgame has the characters outright mention this film by name when discussing their concept of Time Travel.
In the scene parodying the Denver Broncos' game-winning drive in an AFC Championship game, Mark Jackson drops a pass due to a squirrel distracting him. In the 2011 National League Division series between the Philidelphia Phillies and the St. Louis Cardinals, play was temporarily halted because a squirrel ran onto the field. Cardinals fans gave it the nickname "Rally Squirrel" as their team went on to win the World Series that year.
Lou being a fan of Motley Crue and having an enemy played by Sebastian Stan is ironic given the latter would go on to play Tommy Lee.
Just Here for Godzilla: Many people go to this film merely for the group's time-traveling adventures at the end.
Sequelitis: Compare the original film's modest 63% from critics and 56% from audiences on Rotten Tomatoes to the sequel's pathetic 14% from critics and 26% from audiences.
They Wasted a Perfectly Good Plot: The post-credit skits of the gang travelling through different periods of time could have made for a more interesting movie in its own right.