Multiplayer and singleplayer Portal for GoldSource Engine. Half life Portal Gun demonstration video, in c1a0 map. No articles were found. A Half-Life (HL) Skin Mod in the Gauss Gun / Tau Cannon category, by LeonelC. Portal Gun & Gravity Gun fusion (1 of) Trusty Crowbar's Leader avatar. but some videos have portal gun for Half life 1 but must have half life source Here's how you get the Portal gun in HLS (actually its loading the HLS maps in.