Troubled Production: Postal III very much so, according to the RWS website, things were going well with Akella at first until the Russian economy took a downturn, forcing Akella to lay off their A-team that was working on the game. RWS admitted they should've pulled the plug at that point since they knew there was no way Akella's B-team could possibly finish development to their standards, but they soldiered on anyways and Akella took more cost-cutting measures due to running low on funds. To top it off RWS were unable to oversee the last 12 months of development on the game, so it's no surprise it ultimately turned out the way it did.
What Could Have Been: Postal 2 had a some things that were either cut from the game or scrapped. Of course since the game is medium aware, it has a graveyard for them. A list of these things are:
A meat gun, brought back in A Week In Paradise mod.
A staple gun, brought back in AWP mod, like the meat gun.
A rebar gun.
Fire seeking cats.
Fetuses with guns.
"Teen sniper". The name of an arcade machine in the game, possibly a planned mini-game.
The Dude's father as a zombie, to quote the grave: "Zombie Dad".
And last but not least: The games original plot, before it became what it is today.