Batman Forever is a generic popcorn flick that entertains but leaves no lasting impression like The Avengers does. There is nothing wrong with that in a 90s superhero movie. In fact, by that standard it is very good (This was the era of Steel). It lacks the great music and visual flare of the Burton mives, but still has a decent score and actually has a plot where every important character has actual motivation for their actions.
The problem is that another movie was filmed, and only hints of it made it into the final product.
Find the deleted scenes, and you will see the true plot of the movie, an exploration of why Bruce Wayne became Batman that is thought provoking, deep, actually explains the title, and answers many questions and plot holes in the theatrical release. For the life of me I cannot understand why the most important parts of the movie were cut.
Knowing that makes what was once an ejoyable flick with some really cool moments much more painful to watch than it should be.
Unfortunately, there is little to say about the movie as it is. Generic villains who have a prettry cool, if comic booky plot, a Robin that is surprisingly ok, a Batman that sounds as close to Kevin Conroy as we'll get in a live action movie, good action, the best romance of the four movies in the series, though that doesn't say very much, and some odd choices for the design of the batsuit that are rightly infamous.
I did find it very interesting that the only time in the entire movie Bruce Wayne smiled was when he was dressed as Batman, having just decided to hang up the cowl. But that detail is only an aside without the deleted scenes.