Bring up the in-game cheats console during gameplay by pressing the tilde (~) key. Then, insert the cheats listed below for the desired result.
- firstperson - Play in first person
- give item_healthkit - Spawn a health kit
- give item_healthvial - Spawn a health vile
- give npc_alyx - Spawn NPC Alyx
- give npc_barney - Spawn NPC Barney
- give npc_citizen - Spawn NPC Citizen
- give npc_kliener - Spawn NPC Kliener
- give weapon_frag - Spawn a grenade
- give weapon_pistol - Spawn a pistol
- give weapon_rpg - Spawn an RPG
- give weapon_shotgun - Spawn a shotgun
- thirdperson - Play in third person
