On Normal, you have helpful notes strung throughout the mission to help you find your way. There aren’t as many AI, there is less loot to hunt down, and extra powerups are available.
On Hard, you also have notes, but they are more non-specific. All AI are present and there is more loot to find.
On Expert, you’re on your own, with the most loot to track down.
Notes/Bugs
The beta-testers didn’t report any crashes during testing, but this mission may not run on machines with mediocre graphics cards due to the large, open spaces.
When shooting arrows at the giant in the reservoir, they may go “through” him. Aim for his stomach.
Once you have the poison arrows, and you switch to a different arrow, use the “next weapon” key (typically, ‘+’) to cycle back to them.