Half-Life: Portal Gun

Gordon Freeman, meet the portal gun. It's waiting in Black Mesa's HEV suit room, right beside the suit, and Gordon takes it along with the suit. Then play Half-Life's whole campaign with it.

• Blue and orange portals: left click and right click, on any flat surface big enough to hold one, whatever it's made of.
• Look through them: each portal shows the view out of the other, with Portal's swirl and glowing rim.
• Momentum carries through: walk or jump in, or drop into a floor portal and get flung out of the wall one.
• Enemies and objects come through too: a leaping headcrab or a thrown grenade comes out the other side.
• Portal's crosshair: the blue and orange brackets fill in as you place each portal.

Needs Half-Life and Portal on Steam. Single-player. The first time it starts, the gun, its sounds and the portal effects are made from your own Portal install, so nothing from either game is in the download.

Limits: a portal seen inside another portal shows only its swirl, monsters don't plan routes through portals, and portals close when the level changes.

Credits: Half-Life and Portal by Valve, read from your own installs. Game code built on Valve's Half-Life SDK via hlsdk-portable by FWGS, with FreeVGUI. Shared free under the Half-Life 1 SDK license terms (see LICENSES.txt in the download).