What's the thing with all this Lincoln fascination on GiantBomb?? Some internal humor?

yup. Lincoln force is a brainchild of bombsquad.
I can't remember which one, but if you check some of the podcast's around pax time (i think) that's where they started to mold their concept.

A little while ago Ryan pitched a game called Lincoln Force as a joke, go back and listen to old podcasts (sorry can't remember exactly when, think it may have been mentioned at GDC).

He's the best president ever, you stupid motherfucker.  Eh frees slaves, builds log cabins, fights with his stovepipe hat and doesn't afraid of anything.  He went to the moon and killed the communists; he traveled in time and invented the wheel; he told that guy who shot Ronald Reagan that Jodie Foster would totally get on his dick for doing it. 
 
What more do you need?

Im so confused.

a long-running joke, "Lincoln Force, the video game!".  They talked about it a lot, and thought about it pretty deep.  There's this brain in a pod or jar or something, that talks with Lincoln, but it might only be his imagination and he might be crazy... it's great.

Ryan pitched a character-action game like God of War starring Abraham Lincoln on the BombCast right before GDC 2010. It was the episode on which Rich Gallup guested, and so began Giant Bomb's obsession with Abe Lincoln. It's a quality episode of the podcast, and worth a listen.