If you buy Payback and have MK2 GP2X, I suggest you run the colour correction daemon in the background otherwise it can be hard to see.
http://www.gp32x.de/board/index.php?showtopic=37790
You can do yourselves: just put the colour daemon in the autorun.gpu
autorun.gpu: (please save as unix text format)
----- 8< snip -------------------------------------------------
./colourd &
cd /usr/gp2x
./gp2xmenu
----- 8< snip -------------------------------------------------
the colourd binary should be residing on root of sd card. The download version allows you to do as you can put it on the card you like to