From my readthrough:
Take 1st ed AD&D.
Add a heap of new rules to fill in holes in the original ruleset.
Add a heap of new rules for the sake of adding new rules.
Add a heap of stuff for making the game a good-old-fashioned hack and slay fest.
Add a bunch of stuff (a lot of which is rules) which is all the pisstakes you can think of about D&D, in game form.
Make sure that no two rules use the same mechanic, that everything requires a table, and so that it appears the GM is to have little say in how things run.
In short - make a pisstake of D&D, but put so much work into it that it's a complete roleplaying game.
What're you left with? A system that could have been better if it wasn't a parody, and a parody that could have been better if you didn't make a system out of it. And 9 or 10 monster manuals, all filled with (primarily) useless crap, all in alphabetical order, so that if you want to actually use the good stuff, you've got to buy the whole lot.