Hay guys, I played the game. 12 hours on the hardest setting, and that is with a bunch of screwing around and replaying parts to try different things. It is EXACTLY LIKE THE DEMO. All weapons are avail at each lvel. The shotgun and handgun (to get the achievement) are the only thing yo need. If you don't care about achieve, then shotgun and railgun ftw. Game is easy and a joke. Funny one liners, but it is Serious Sam and Postal in 1 game.
The dick, tit, fart, wiener, jokes get old real quick.
Can probably play the game straight in 8 hours.