A lot of people have asked me how to enable singleplayer mode in the mod, so I'll explain how to do it here (the player guide does explain it, but a lot of people don't bother reading it through).
First, simply start the mod, and in the main menu, bring up the console by pressing the tilde key below Esc (it may vary from keyboard to keyboard; for US keyboards it's usually ~). Then type "sam_bEnableSinglePlayer=1" (without the quotes) and press enter. An option called "Play Singleplayer" should now appear in the main menu.
After that you can access the singleplayer mode normally just like in normal Serious Sam 2. However, due to the increased/changed power of the weapons, we recommend playing it in a harder difficulty setting, such as Hard or Serious. Also, note that we do not officially support the singleplayer mode, so it may have some undiscovered bugs and issues. The weapons work the same as in DM mode, except the Kazi Bomb, which no longer kills you, and grant the same speed bonuses (you will also run at DM speed). Any large treasure items will be replaced with Invulnerability powerups (this was a leftover code, but it actually works okay :P).
