You can now download a free Angry Birds Seasons: Easter

15 Seasonal levels

5 Seasonal themes

Requirements: Compatible with iPhone, iPod touch, and iPad. Requires iOS 4.0 or later.

Read more and get it from here

If you do not have an iPhone, iPad etc, you still can play Angry Birds for free  if you have a Windows 7 PC, read more here - Free Angry Birds Game Full version for PC - Windows 7