Codename: Gordon was released over Valve's Steam online delivery system on May 18, 2004, as a promotional game for the then-upcoming Half-Life 2. It was free 2D sidescroller shooter developed by NuclearVision. Even though the game was later removed from Steam, it still has Steam forum page, and can be installed on Steam client with direct installation link (copy the link to address bar and press Enter, Steam client will be launched and start downloading the game)
The version presented on our website is standalone, it doesn't require Steam, just extract the archive & play
Russian 
Comments and reviews
This game that I remember firstly, from the day that I discovered the PC Mania DVD edition, which is a "demo game", along with a bundled FPS game, Doom 3, and its 200 flash games. In 2010, I was aged 21, and that was my first PC game played, as where my gaming rises.
very good game but I'm sad they removed it on the steam store
languages not working...
This game is on steam, but it doesnt have a store page just like Spacewar.
Well, no. You can still technically get this game on Steam you just have to go to the game's PCGamingWiki page to figure out what the browser protocol is.
Or if you don't have time, here's the protocol needed: steam://install/92
No comment nor review for this game at the moment.