Im making a First Person Shooter and im making all the textures, proggraming and everything myself its comming along very well, im looking at about 8months to 1 more year of work!.
Ill leave updates here soon! 
Good!
I also made a loading demo in that post of yours: https://blenderartists.org/forum/viewtopic.php?t=28139
Explore the logicBricks, then you can implement it.