[Klaster_1]

>having to choose whether to walk through the easy, normal, or hard doors in game to set the difficulty level was a nice touch i'd never seen before.

Have you played Quake 1 campaign before? That literally what you do at the start - walk through one of three doors.

[quantummagic]

No, never really played video games much. I suspected it was only new to me, but it made a strong impression, it is such a clever idea.

[unbalancedevh]

And then there's the "nightmare" difficulty, but you have to find that hidden door!