Chicken Invaders has always been popular for its humour and addictiveness, and now it is on your PSP.

Changes:

SOUNDS!!!!! due to the huge response from 1.1
level display (the “level 1 wake up!” thing)
better points system
improved graphics
reduced lag by taking out a fifth of the explosion particles
reduced lag by decreasing firing rate
increased present drop rate
boss chicken moves everywhere, not just side to side
level 4 changed because the chickens heads went out of the screen
fixed the rocks dropping drumsticks LOL!
increased hyperspace speed
added version number text on title screen

http://forums.qj.net/psp-development-forum/156929-release-chicken-invaders-version-1-2-kairus101-23-08-2009-a.html