Tick Tick Boom is the first part of Act 2: Nightfall, and it sees the player first encounter the Boomer and the Boomshot as a wieldable weapon. It is also the location of the thirteenth COG Tag in the game. In this part, the player once again can choose one of two paths to take. The left path - the low route, or the right path - the high. It is recommended that inexperienced players take the Right path, as they do not then come into direct contact with the first Boomers of the game.