I actually sort of enjoy Batman Forever, because - let's be honest - neither of Burton's Batman movies were exactly perfection either, and Forever at least has a kind of endearing camp gleefulness.
But it was still a mess. Hell, they screwed up Two-Face's big introduction shot by cutting to the security guard at the exact moment they should have been revealing that he had, y'know, two faces
. And that was right at the beginning, so it set the tone for the rest of the film. The horrible screeching score ("BLUWAAA! BLUWAAA! BLUWAAAaaaAAAAaaaaAAA!"), the 5 mph car chase, the out-of-nowhere Sonar Batsuit to save the day and especially Two-Face's split personality being almost entirely ignored in favour of literal "Muwah hah hah!" Jokerisms were all dreadful, while Kilmer and Kidman were just... bland.
Carrey was still fun, though. For some reason, the game of Battleships and his line of "A waterrrrrry GRAVE!" always get a laugh from me.