I found an epic way to end Half-life refusing G-Mans offer. Quoted from a troper from TV tropes, "Gordon will want to accept G-Man's offer, after all he's mentioned having to find a new job. However, Gordon will spend so much time rambling to himself that the window to accept the offer will end and G-Man will teleport him into the room with the 30 alien grunts, while Gordon screams that he wanted to accept the job. But Gordon will reveal that there was one weapon G-Man forgot to confiscate: the crowbar. The series will have a Bolivian Army Ending as Gordon screams and charges at the grunts, crowbar in hand."