Unlock Hair
Area 51 Hat:
Get to level 3-1
Blond Hair:
Beat last boss on hard
Curly Hair Wig:
Destroy the “Fish are like plants” building in level 1-5
Diamond Tirera:
Beat level 2-2 on Hard
Pirate Hat:
On level 1-1 destroy Hairy Nanny Daycare
Soviet Hat:
Get to level 2-1

Private Eye hat:
Beat level 3-2 on Hard
Jouster hat:
Beat level 3-4 on Hard
Tom Fulp hair:
Name your Hominid Tomfulp

Hidden Hats
At the Options Menu where you can rename your alien enter the following names to unlock hidden hats for the two player game.
abe
april
dandy
cletus
goodman
grrl
princess
superfly