how many sources do you intend to get?
on a linux debian system (you then probably know how get sources easly), command
#apt-get install apt-redepends
$apt-rdepends -r python-pygame
return (at least):
angrydd
ardentryst
balazar3-2d
balazar3
bambam
bouncy
bubbros
castle-combat
childsplay
ffrenzy
fofix
freealchemist
freevial
fretsonfire-game
fs-uae-launcher
funnyboat
impressive
krank
lightyears
magicor
monsterz
oneisenough
opensesame
pathological
psychopy
pykaraoke
pyntor
pyracerz
pyrocket
pyscrabble
pysiogame
pysolfc
pysol-cardsets
pysycache
python-box2d-doc
python-elements
sugar-physics-activity
sugar-pippy-activity
sucrose-0.96
sucrose-0.98
python-freevo
freevo
freevo-lirc
python-kivy
python-kivy-examples
python-pyepl
python-pykaraoke
python-pymt
pyvnc2swf
renpy
renpy-demo
renpy-thequestion
seahorse-adventures
singularity
slingshot
snowballz
solarwolf
whichwayisup