Enter the Statue Of Liberty museum across from the Test Of Valor. There is a 
breakable wall that looks like it is made of straw. Slice it open to find a 
silver Xbox that will fully restore your health an unlimited number of times.
Easy Yellow Essence in Chapter 6 
Just after the Giant Skeleton mini-Boss, you will encounter more Scorpion 
Skeletons. Fight and Wall Run your way through until you get up a floor. Then, 
drop down, and make your way back up to get more Yellow Essence. Repeat this as 
many time as desired. -From: Mark Winzenread
Easy "Feat Of A Hundred Slashes" achievement in Chapter 6 
Before the Giant Skeleton mini-Boss, a large number of Scorpion Skeletons will 
attack. Jump around them, and throw shurikens until you reach a 100-hit combo.
Vigoorian Flail in Chapter 9 
Immediately after you defeat the tunneling worm mini-Boss and follow the path it 
makes out, there will be a small fork in it. If you take the fork to the right, 
you should find yourself climbing a small hill. Atop the hill is a corpse. 
Examine it to find the Vigoorian Flail.