Portal: Prelude 1.1.5

Mods are some of the best community-created content out there. If you as a developer have an active modding scene, then you can guarantee that your game will last much longer than other games that don't have the same thing. Half-life games are especially popular, due to how acclaimed the game was and how easily moddable the engine is. Portal: Prelude is one of many source engine mods out there.

To install Portal: Prelude, you must have Portal installed. Then, run the installer and you're good to go.

This game's story takes place before Portal 1. Initially, the setup seems the same. You're a test subject testing out the handheld Portal Device. However, this time, every single scientist in the Aperture Science Enrichment Cetner is still alive. 

The biggest problem with this mod is the pacing. This game's difficulty curve is all over the place. It doesn't assume that the player has played the game already like another Portal mod does, but it also doesn't ease the player into the game either. Instead, there are random peaks and valleys all throughout the game in terms of the difficulty curve.

However, it's also one of the most popular Portal mods around for a reason. This mod has some challenging rooms that are incredibly satisfying to solve, and there is also a pretty well put together story as well with an interesting arc. All in all, Portal: Prelude is still a worthy mod that has stood the test of time for quite a while.