I think the TV show MASH! is based on this book, although based on the wrong war. It has the same warped sense of humour. It's the ironic and bitter kind of of a man that has served in an ineffectual army with superiors that should never have been promoted.
The bitter humour does very well to alleviate some of the horror depicted throughout the story. A young boy getting cut in half by a show-off pilot, then that pilot killing himself by flying the plane into a hill; a man mistakenly thought dead, who couldn't stop the paperwork and then his family believing he was really dead; and the police brutality and senseless killing. The stupidity of the superior officers, the games they play, and the mindless decisions they make that result in many deaths. Sometimes humour is
Yossarian is the main character. He's an anti-hero. He's unlikeable, difficult, crazy, and you never get a really good sense of who he is. One moment he's moral, the next moment he's an anarchist. One moment he's a breaking up fights, the next moment he's causing them. One moment he's falling in love, the next moment he's hurting people and planning to kill them. Despite all this, he still attracts a small loyal group of other officers, and you do start to find yourself empathising with him.
The few female characters in the book are either used for sex by the officers, or they are whores seeking officers out. They are trying to survive in the ways they know how, in a country that has been under a dictatorship for years and who have just been liberated. Other than the American army men, there are no healthy young men left, and there seem to be few jobs and lots of orphans. The Italy portrayed by Joseph Heller was not healthy at the end of WWII.
It's a difficult book to read. The first half of the novel doesn't move forward in time - it keeps circling back on itself and twisting story lines, linking various characters. There are lots of character, but each are so unique that it's not hard to keep track of who's who. Joseph Heller does not portray his characters nicely, nor are they handsome or particularly talented. They all have a lot of issues, increased by the war, but most were already neurotic and selfish.
Catch-22 is some made up policy that the officials use to justify their decisions. 'They have the right to do anything that we can't stop them from doing', and you can't get out of the army for being crazy because by wanting to get out the the army you prove that you're sane.
Everyone should read this.