I have a psp go on 6.20 tn-e
But it says i need to update my psp to be able to play the demo :( i don't want too lose being able to play my backups for this demo ;__; please help me is there another way?

Upgrade to 6.39 PRO

I think you should upgrade to a newer version because the game is made to be played in a newer version.

or you could try 6.20 PRO-B8..

Yea the demo will want to run on OFW 6.39 or 6.60

Updating to a more recent custom firmware may help, or wait for the demo to be patched.

I'm on 6.20 PRO-B9 (Beta) and it runs fine

Im on a psp go can someone help me with this?

1. update to 6.39 ofw
2. get 6.39 pro b-8 http://code.google.com/p/procfw/downloads/list
3. download the demo(not the iso)