person ▁shoot er ▁game play ▁mechan ics ▁as ▁Half - Life ▁ 2 . ▁The ▁game ▁is ▁viewed ▁from ▁the ▁perspective ▁of ▁the ▁player ▁character , ▁and ▁plot ▁information ▁is ▁im part ed ▁through ▁script ed ▁sequences ▁rather ▁than ▁cut sc enes . ▁A ▁heads - up ▁display ▁at ▁the ▁bottom ▁of ▁the ▁screen ▁shows ▁the ▁player ' s ▁health , ▁energy ▁gauge , ▁and ▁am mun ition ▁status , ▁while ▁available ▁weapons ▁are ▁shown ▁at ▁the ▁top . ▁Health ▁and ▁arm or ▁energy ▁can ▁be ▁re pl en ished ▁by ▁pick ing ▁up ▁medical ▁supplies ▁and ▁energy ▁cells ▁respectively , ▁or ▁by ▁using ▁wall - mount ed ▁charg ing ▁devices . ▁The ▁player ▁character ▁is ▁equ ipped ▁with ▁a ▁small ▁arm ory ▁of ▁weapons ▁from ▁Half - Life ▁ 2 ▁at ▁the ▁beginning ▁of ▁the ▁level , ▁including ▁a ▁p istol , ▁shot gun , ▁cross bow , ▁and ▁gravity ▁gun . ▁The ▁gravity ▁gun ▁allows ▁the ▁player ▁to ▁manipulate ▁physical ▁objects ▁in ▁the ▁world ; ▁it ▁can ▁be ▁used ▁to ▁pick ▁up ▁nearby ▁objects ▁and ▁throw ▁them ▁at ▁enemies ▁or ▁create ▁cover ▁from ▁enemy ▁fire . ▁The ▁gravity ▁gun ▁can ▁also ▁be ▁used ▁to ▁perform ▁several ▁non - com bat ▁functions , ▁such ▁as ▁gra bb ing ▁out - of - re ach ▁supply ▁cr ates . ▁ ▁Story ▁ ▁Half - Life ▁ 2 : ▁Lost ▁Coast ▁opens ▁with ▁the ▁protagon ist , ▁Gordon ▁Fre eman , ▁finding ▁himself ▁near ▁a ▁group ▁of ▁decay ing ▁pi ers , ▁under ne