Portal 2.5 is a fan game for Valve's video game, Portal 2. The game starts where Portal 2 ended, so you should finish playing Portal 2 before playing this, to avoid spoilers. The story explores some theories about the characters. This has some puzzles and interactive choices, by it's mainly linear. It's meant to be taken more as an interactive piece of fan fiction rather than a game.

　　Praise for Portal 2.5 firiami.tumblr.com:

　　This reminds me so much of those old RPGs I loved so much as a kid! ... I just bought a last generation game and yet I had more fun playing this for a whole hour and a half ... nicely done. moose-vale.tumblr.com:

　　Okay I have been playing this for literally 10 minutes and I can already tell you [that] it's adorable and well made you Portal fans better get ... in gear and play it r/n. (sic) butterflyfractals.tumblr.com:

　　Thank you! Thank you! Thank you so much for this experience!!!!! ... Every portal fan should play this! Links Downloads include a postmortem PDF. It can also be read online: DeviantART.

　　Official website page for additional links.