Metro: Last Light - Faction Pack(2013)

The Faction Pack is the first downloadable content pack for Metro Last Light included in the Season Pass. It features three missions set aside from Artyom's journey but it can be presumed they are canonical. The levels included are Heavy Squad, Kshatriya and Sniper Team. Each level is based on a certain gameplay mechanics, shooting, stalking and sniping respectively. The developer blog for this DLC is here.