: Players can customize their characters with various hats, some of which are animated or can be manually added via mods.
: Supports up to four players at once, each with their own portal gun for chaotic co-op gameplay.
: Includes an in-game level editor and supports community-created "mappacks," including recreations of the original Super Mario Bros. and specialized Portal puzzle packs.
: Includes unique cheats and game modes, such as a "Minecraft" mode accessible via the Konami code. Technical Details