Pretty sure it's not the opengl.txt file. The games just not running without it because that's the file that tells it what resolution to make the window among other various graphic stuff.
The persistent file in the %appdata%/roaming area look like it's associated with saving and loading files. Though it's possible winterwolves is using it to determine if you've bought the game or not. (I only did like. 3 minutes of research on it. >_> <_<)
I tried running the game, after throwing in the opengl.txt from the demo version, and loading up a save at the "This is where the demo ends" screen. It said I slept great, (Skipped the Demo end screen!) and then crashed. "ScriptError: could not find label '('C:\\- indie dev -\\games\\renpy.new\\Remember Me/game/simulator.rpy', 1299339157, 4)'."
I tried throwing in the simulator.rpy from the demo version but that made the Demo end screen pop up again.
(Also, If someone could upload this planet stronghold persistent file somewhere that'd be great.)
</textdump>