Blacklight: Tango Down is an online-only multiplayer first-person shooter. It is based around a struggle between two military groups: Blacklight and The Order. Blacklight is a covert ops unit that is brought in to investigate the disappearance of one of their own, Colonel Klein and his team of Blacklight operatives. Traces quickly point to The Order, a rebel group composed of ex-US special forces and local militia, and they also have access to high-tech military technology. Online battles support up to 16 players and the game is divided into 4 Black Ops missions (related to the story) that can be played alone or cooperatively (with up to four players), and regular multiplayer matches across 12 maps in 7 game modes.
The game contains a ranking system similar to Call of Duty: Modern Warfare 2 with 70 levels. When players advance they get access to skill and experience points, as well as items to customize the weapons, such as magazines, muzzles, weapon tags, and stocks. All items are stored in an Armory and different weapon configurations can be saved. Players can also determine grenade and equipment loadouts, character armour, and camouflage. Ammo and health can be refilled while playing, through stations located in the world.
Players have access to large arsenal of weapons, as well as high-tech items such as a Hyper Reality Visor that provides immediate battlefield intelligence and allows players to see through walls with specific colours for friends and enemies. This can be countered with Digi grenades that disrupt the view with glitches, and EMP grenades that force the enemy visors into a reboot sequence.
The different multiplayer modes include deathmatch, team deathmatch, retrieval (capture-the-flag with a data canister), detonate (similar to bomb planting in Half-Life: Counter-Strike), domination (capturing and controlling specified points), last man standing, and last team standing.