This is possible the most frantic anime I have ever seen. Retro and Panda, who look like characters straight out of FLCL awake on a dark street with no memories and a yen for violence. After a violent robbery and chase scene they are packed of to a prison of no return on the moon. They are fed, purges, and packed of into a cell where a momentary indiscretion somehow catapults them into a jailbreak.
From this point the story becomes on long chase and fight scene, complete with escalating bosses at the end of each level. In bits and pieces we find out Retro and Panda's previous history, and the secrets behind the walls of Dead Leaves. Nothing really ever quite makes sense, but it really isn't necessary that it does. Dead Leaves is a 'show off' piece, where twisted creativity and virtuoso animation are the real purpose of the show.
It's hard to believe that this comes from the same people who put together the atmospheric "Blood: The Last Vampire" and the beautifully drawn "Kai Doh Maru." The closest analog would be the aforementioned FLCL, without all the quiet parts. The first watching leaves a chaotic impression and it takes several more viewings before you start to pick up on a lot of the sight gags.
This isn't going to be everyone's cup of tea, especially for a US audience which has become accustomed to the new generation of anime. But it is fun in a loud, lewd, hyperactive fashion. At the first viewing the writer confided that what he wanted was for the audience to get drunk and start dancing. I'm not sure if it will take you that way, but it gives you a good idea of the driving force behind the film.