Here's a couple secrets I found out. On the sides of most mountains, there is a hole. Sometimes once you go in the holes you have to jump around, holes usually containing mushrooms, keys, and hidden pathways. To earn flight, its very simple. The first temple you will come across will have one tree. However, this isn't the temple you need! Far ahead is another temple, much alike to the first. It has two trees and in the middle is a small block. Sit on it for about 15-20 seconds until it tells you that you have gotten flight. I read the comments and saw that people have been getting easily annoyed with the snake. You will have to collect 5 flies to activate the rune and make the snake disperse. How to do this is by noting this pattern. The snake eats the flies when its mouth is open and you are on it. It'll start either up or down with its jaws parted. Then it'll be on the bottom with its mouth closed. While its mouth is closed, hurry to the top and get any flies.
Like Recovery said, a sequel with additional squirrels would be a very nice addition. (: I also find this game rather addictive, and even I a female, find it rather enjoyable to use the guns.
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 "William and Sly"){kind=icon}
 "Defend Your Nuts"){kind=icon}