I am an Amateur Artist, Mapper, Musician, Coder, Voice Actor and Modeler. I am currently working with Dubbz Studios and Shattered Studios.
Mod Review on Jul 5th, 2015
The page for this was made late 2012, Garrys Mod has been out since before 2009.
Now Im pretty sure this game isn't trying to rival Garry's Mod but seriously, release crap and you should just expect bad reviews. It isn't even a mod, its an extension of Half-Life.
How to recreate in HL2:
Bind Z, X, C, V, B, N and M to spawn Zombies, Citizen and Metrocop
Bind Y to Noclip
Give Phys Cannon - physcannon_mega_enabled 1
Bind V or Q to Noclip
Bind , npc_create npc_alyx