That would indeed be a great mod, but not if you are following Gordon’s steps all the time. Where would the puzzles come in? Gordon would pretty much clear the way for you.
I like this idea.
The Oddworld games were fun.
That kinda does sound cool 
Copy the actions to make the scientist do up his rediculous tie. the first one done gets ten coins!
hmm, I like where this is going.
Pack G-man’s suitcase.
Crowbar pong?
Black Mesa Platforming o/
i agree with collgreek!
I think people are seriously missing the true beauty of this idea… has no one seriously considered just who you’d be playing as for this idea to work?
You’d have to be playing as Gman.