Lambda Coop is a gamemode for Garry's Mod. So, you need Garry's Mod on steam.

Download "Lambda Coop" and "Any Gamemode Customizable Rocketjumps"

If you want to run HL2 w/o cutscenes, download "Cutsceneless Mod" and remove HL2 from "Games" tab

If you want to run HL2 w/ cutscenes, just add HL2 in "Games" tab

Join to Random HL2 map and type in console these commands:

• lambda_connect_timeout 0
• lambda_max_respawn_timeout 0
• lambda_map_change_timeout 0
• lambda_allow_auto_jump 1
• lambda_auto_jump 1
• lambda_playercollision 0
• sv_sticktoground 0

ABH:

If you want to run category with ABH, type in console "lambda_abh 1"

If you want to run category without ABH, leave it as is

Binds:

bind <key> "kill" - This bind is needed for killing yourself, needed for some skips

bind <key> "lambda_reload" - Restart with loading (such as save deletion)

bind <key> "lambda_reset" - Restart without loading