The napalm kinda gun is not shown in the Fileplanet video. It is however seen in a gamespot video. The video starts off with these flying things chasing Gordon, after running away from them Gordon takes out the napalm gun. Shoots a combine above him and then takes the other out with a pistol. This gun shoots like an arc, like a grenade launcher. It is a rather big gun too. This gun is in the 4th Gamespot movie of E3 coverage.