Add pixen
Added some engines and blogs&Portal
Add gamedevs.org to blogs and portals
Add Java-Gaming.org to blogs and portals

http://www.java-gaming.org/ is a very nice and active community of (java) game developers, has a lot of great resources in their forum.
Merge pull request #21 from Phonbopit/master

Added some engines and Blogs&Portal
fix conflicts
Update project description
Add Game Development on StackExchange

Add http://gamedev.stackexchange.com/ to "Blogs and Portals".
Merge pull request #24 from Zolomon/master

Add Game Development on StackExchange
Add Real-Time Rendering to Blogs/Books

Real-Time Rendering is a book that covers state of the art shading techniques, and the accompanying website has a lot of good reference material and news about the computer graphics industry/research department.
Merge pull request #25 from Zolomon/master

Add Real-Time Rendering to Blogs/Books
Remove description on iforce2d
Add some lessons and another great book
Add computer graphics link
Merge pull request #27 from Zolomon/master

Add lessons and books
Add awesome book and KhanAcademy
Merge pull request #28 from Zolomon/master

Add awesome book and KhanAcademy
Update README.md

add 2 engines - framework 2d
Update README.md
Update README.md

:+1:  @ellisonleao