Here is the full list of all 18 Booom-Slang! achievements.
Beat Eastern Escape - Act 1
Beat Eastern Escape - Act 2
Beat Eastern Escape - Act 3
Beat Desert Disaster - Act 1
Beat Desert Disaster - Act 2
Beat Desert Disaster - Act 3
Beat Terrifying Tundra - Act 1
Beat Terrifying Tundra - Act 2
Beat Terrifying Tundra - Act 3
Beat Castle Cataclysmic - Act 1
Beat Castle Cataclysmic - Act 2
Beat Castle Cataclysmic - Act 3
Beat Metro Manic - Act 1
Beat Metro Manic - Act 2
Beat Metro Manic - Act 3
Beat Sci-Lab Synaptic - Act 1
Beat Sci-Lab Synaptic - Act 2