When you complete the game go into the trophy room then click on the card you got from the last mission then you will be transported to the enter messages section :)
Oh and also there is a glitch on level 9 when you run out of bullets it doesn't reload :@
At the end it says:
I did it... I can fly...
(Then it's him flying, but then he crashes into an iceberg and it says)
And that's why nobody believes that penguins can...
LEARN TO FLY (title screen pic.)
Then it says:
You cleared it in:
XX days
It was about time...
OMG Chariblock thanks! I tried the 1st one but it just messed up my game lol but then I did the second one and I hit 777's with a normal attack and i'm level 11! OMG!
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 "Fat Slice"){kind=icon}
 "Galactic Gravity Golf"){kind=icon}
 "Pandemic 2"){kind=icon}
 "Gravitee"){kind=icon}
 "Bubble Tanks 2"){kind=icon}
 "Learn to Fly"){kind=icon}
 "Sonny"){kind=icon}