Half-Life: Day One

Half-Life: Day One is the initial pre-release demo of Half-Life. It was designed exclusively for OEM partnerships and was often bundled with graphics cards. It was never available to the general public. Half-Life’s proper demo (available free to the general public), is Half-Life: Uplink, which was released several months after the full game.

Plot
Day One begins at the same point as the full game, but ends after the player completes the chapter "We've Got Hostiles", at the end of the first day of the game's plot. The levels accessed in this demo are overall identical to those that appear in the full game.

Gameplay
The demo does have some minor gameplay differences from Half-Life.


 * It is possible to crouch-walk faster.
 * The console cannot be activated.
 * The HD pack cannot be installed.
 * The Glock 17's magazine holds 18 rounds instead of 17.
 * Up to 25 grenades can be carried instead of 10.
 * Grenades don't explode if they're cooked for too long.
 * It is possible to throw grenades further.
 * The MP5 already has 50 rounds in magazine when picked up.
 * Four shells are not kept in reserve when picking up the shotgun.
 * The shotgun's pump sound is always heard at the correct time.
 * Ammunition for the pistol and the shotgun contains 30 rounds per box instead of 17 or 12.
 * The Long Jump Module shown in the hazard course looks like a battery instead of a jetpack.
 * The HEV battery has a different appearance.
 * Neither the pistol nor the MP5 reload automatically after emptying a magazine.
 * There is no secondary attack for the pistol; it can only fire in semi-automatic mode.
 * HUD sprites: featuring early RPG icon, unused battery-style armor indicator, less sprites for 320 screen width, 320x sprites do not feature the bar near the man showing suit power.
 * Partial player profiles system support.
 * Some chapter names are different.
 * The HECU Laser Tripmine uses E3 1998 model.

Weapons

 * Glock 17
 * Crowbar
 * Mk 2 Grenade
 * HECU SPAS-12
 * Laser Tripmine (placed only, not usable by the player)
 * MP5

Allies

 * Black Mesa Security Force
 * Black Mesa Science Team

Enemies

 * Barnacle
 * Bullsquid
 * Headcrab
 * HECU
 * Houndeye
 * Vortigaunt
 * Zombie