Counter-Strike

One of the most popular mods out there even to this day. So popular Valve went as far to make it official.

Team Hiring
It appears that there were plans for hiring teammates. In the GameUI.dll file, there is text that reads:

%s is not available for hiring!

"%s" would stand for the member you were trying to hire.

Unused Weapons/Equipment

 * CS Grenade: A smoke grenade that is it...a smoke grenade. Anyways two HUD icons and a kill icon remain.
 * Flare: Whats the deal with flares and Valve? Are you mocking us Valve? Anyway, two HUD icons and a kill icon for it still exist.
 * Gas Mask: A gas mask to most likely combat the effects of the CS Grenade. Only two HUD icons remain.
 * M60: Going Rambo on Terrorist? Sounds fun, but sadly only a HUD icon and kill icon are still there.
 * M72 LAW: A rocket launcher strangely called "LAW Grenade". You all know whats left.
 * Machete: Two HUD icons and a kill icon shows it was going to be in the game at one time but interesting enough the icons don't even look like a Machete but a Kukri.
 * Molotov Cocktail: Good ol Molotovs were cut from the original. HUD and kill icons are leftover.

Region Differences
The USK 16 German version has much of the same censorship featured in Half-Life, such as having enemies sit down and shake their head when they get shot and turning the blood yellow. In addition, all the hostages the same character model, removing the researcher models. The German Steam version, rated USK 18, completely removes the blood.