There is no question about it that this is one of the worst movies in film history. And that it definitely is a bad one in the Batman film franchise. But how bad is it? I will try to answer this.
For a long time I considered Batman Forever to be a step up above Batman & Robin but I don't feel this is longer the case. While there is no denying that both will disappoint on so many levels there is something about Batman & Robin that could redeem itself somewhat. Mind you you really have to be in a certain mood for that to happen since it requires a lot of suspension of disbelief and patience. So in what way does it redeem itself? Simple. Joel Schumacher probably realized that his take on Batman was quite campy and that it was time to let go of any lingering seriousness and embrace this campiness. Does he succeed with this? In parts yes. This film is more a return to the sixties Batman with Adam West where everything is upbeat and colourful to a degree that it can overwhelm you. The only things are missing are the sounds and text balloons with pow and poof. Everybody is at their wackiest. Even George Clooney, Schwarzenegger and Uma Thurman aren't taking themselves seriously. Alicia Silverstone is not even trying to give a crap and she basically is playing a feminist version of her Cher character from Clueless. Chris O'Donnel is probably the only one giving a damn and tries his best until he realized it was no use and went along with all the craziness. Michael Gough who plays Alfred was very aware of the path taken in Batman Forever but remains professional until the end.
Like I said in parts it worked. But sometimes it simply did not and then it becomes a real chore to remain watching. I can assure you that it will only take you five minutes or so to completely forsake this film and not caring about anything that happens. Batman not trusting Robin? Alfred dying? Schwarzenegger overusing his one liners? Poison Ivy wanting to save her precious plants by killing all the people in the world? Bane just a mindless thug? Whatever. You won't care. The saving grace are the little interactions between the actors pretending to be the characters they supposedly are to portray and making all kinds of in jokes the public isn't always in on. With the result that some jokes are incredibly effective and some fail miserably. But knowing this adds a fun factor to the viewing experience. You could for example play a drinking game where you have to drink every time Mr. Freeze does a one liner. Or you have to drink when Poison Ivy talks like someone from the thirties. What was that about?
So besides drinking is there any other reason to watch this? No, really don't bother. It's very hit and miss when it comes to the B movie badness. It often is just plain bad. The few so bad it's good scenes won't make up for that torture.