What sequels had a major change in tone because of audience feedback of the previous movie in the series?

You mean, kinda like the funnier tone associated with Justice League, coming from the negative feedback to the droll Batman V Superman: Dawn of Crap?

I can think of two series:

Star Trek V "tried" to become so much funnier, based on the levity brought upon Star Trek IV.

Similarily, Freddy Krueger became more of a comedian in Nightmare 5, based on the levity brought upon Elm Street 3 and 4.

On a different note, Rocky IV resorted more on 80's pop-culture rock montages, rather than Bill Conti orchestral moody overtures, based off the audience positive reaction to the rowdy "Eye of the Tiger" witih Rocky III

Evil Dead II to Army of Darkness though that may be debateable

How do we know any of this is from audience feedback?

The only one that I can think of that had a major change in tone/storytelling was the Fast and Furious series. It started essentially as a glitzy muscle car racing movie and then the tone changed dramatically in part 5 to an ensemble heist action series.

Lethal Weapon 2 went from a gritty buddy cop movie to a gritty cop movie with a lot of humor. And a fairly big change in Riggs's character.

Off the top of my head:

-Batman Returns-Batman Forever-Batman and Robin-Batman Begins: Batman Forever was changed to be more kid friendly after the parental backlash from BR. Then after audiences crapped on B&R they changed Batman Begins back to being more dark.

-Temple of Doom-Last Crusade: Parents complained about how dark Temple was and the tone was lightened up for LC.

-Ghostbusters-Ghostbusters 2: They made GB2 more kid friendly because the The Real Ghostbusters cartoon was a big hit and the original was popular with kids. They also changed Janine to make her look more like her character in the cartoon.

-Robocop 2-Robocop 3: Tone was changed again in order to make the movie have more of a presence with kids.

-Teenage Mutant Ninja Turtles-Secret of the Ooze: Parents complained about how dark the first one was so the second took out all profanity and the turtles never used their weapons.

-Highlander 2-Highlander3:Highlander 2 was pretty universally hated so they rebooted Highlander 3 to forget the events of the second movie.

Goldfinger

This; Hollywood listen to feedback?

The Flintstones 2... the first was all sexual and dark. The second, not so much

They're a business, so they do.

Star Trek II certainly did. Maybe not directly due to the audience, but certainly because producer Harve Bennett thought the first movie was boring.

28 Days --> 28 Days Later

That was a change in tone I sure as shit wasn't expecting!

Keep telling yourself that. Other influences sure not the audience.

Thanks for all of the replies. Interesting that most sequels that do have a noticeable change in tone have a lighter tone compared to the previous film in the series.

Gremlins 2 was basically turned into a parody because the original was considered rather dark for a family film.

But really, many movies are changed by audience feedback before most people ever see them.