For everybody here who doesn't have a clue:
GREEN IS A PRIMARY COLOR.
There are two color systems, additive (aka colors of paint) and subtractive (aka colors of light). The primary colors of paint are red, yellow and blue. The primary colors of light are red, GREEN, and blue. And because its subtractive, red+green=yellow. The reason this games uses the light color system is because that is the system computers use (your screen displays light, not paint). Stop complaining that the primary colors you learned in your first grade art class aren't the same primary colors used here. Science is more important than watercolors.
The Shaman isn't 'randomly picked'. It's chosen based on a points system. When you get the cheese, you get points. If you have the most points at the end of a round, you become the Shaman, and then your points are reset.
3 Problems:
1. The challenges that involve killing all enemies with a certain weapon get considerably harder with Armageddon and drills, which kills from don't count as weapon kills and can't turn off.
2. I bought everything and didn't get the medal for it.
3. The 'free chainsaw' perk choice doesn't go away after you purchase the chainsaw.
The higher level location you visit, the longer time it takes to reach. That's why a low level character could reach places faster than a high level character even if it had high teleportation.