heh, most of the games I play have have everything pretty much uncovered; at least half of them have had source code released into the GPL. Doom, Quake, Quake 2, Duke Nukem, etc.
For some reason I can no longer play them on easy skill. I have to play the quakes on Nightmare, Doom on ultra-violence (nightmare is a... well a nightmare) and duke on *censored* I'm good; strange how I can cope with respawning enemies in Duke but not Doom.
And I understand the "completing everything in the game" notion; still working on getting to level ** with my characters in chrono trigger, for example.
The only gameplay style I detest is the "buy game, look up cheats, use cheats, beat game" method.