I was wondering if there are any known PSP games that are incompatible with the PSP Go? By that I mean actually incompatible, as in they won't run even with the latest CFW due to missing/different stuff in the firmware.
Uhm, I'll blindly speak here but.. you should be able to play all games since they are designed to run under the PSP machine as whole. At least all games I've tried have worked successfully.
Keep your CFW updated and you'll be fine.
So I take it 6.20 Pro-B10 will run just about anything, including games that normally require 6.60?
In my experience the only things that don't work on the Go are some specific versions of POPSloader and maybe some random homebrew/plugins. For example, I tried to get Digimon World 3 running using my own ripped ISO and all of the threads I've read discussing compatibility say to run it with 3.71 or something like that, but almost every early/middle-version of POPS won't work. You shouldn't have any trouble getting games to run, as compatibility without those versions is near perfect, but every once in a while you might find one or two games that have problems with later versions. That said, I did get the game to work using the really early versions of POPS but those require you use headphones to get sound for some reason.
Did Birth by Sleep ever came out to the playstation store? If not, then that would be "incompatible" with the Go