Remember when Valve made two ingenious puzzle games about portals and failed to count to three? These days, the hallowed halls of Aperture Labs only come into play when Valve needs a quick and quirky tutorial for the latest VR hardware or PC handhelds. But the portal's community never stopped testing. For years they have been uploading new test chambers, original stories, and entire fan campaigns to the Steam Workshop.

This weekend, something big dropped. [The name of the game is Portal: Revolution. It's a completely original 7 hour campaign with new characters, mechanics, and a storyline between Portal 1 and Portal 2. It's a huge mod, so much so that developer Second Face Software released it with its own standalone Steam page and a thumbs up from Valve. Revolution is still very close to Portal 2, so you'll need to own Portal 2 first, but according to Second Face, the upgraded engine makes it possible to do things "that were not possible in Portal 2." The company says that it has made it possible to do things that were not possible in Portal 2. I've played nearly two hours so far, and I'm beginning to see what he means. Revolution is not just "more Portal."

The beginning is; in a strange echo of Portal 2's opening, you play as an unnamed Aperture test subject awakened by an AI core named Stirling decades before Chell was unearthed by Wheatley. Stirling is a hilarious and cartoonish maintenance core who is trying to restore Aperture after it was destroyed by a "monster," but needs human help.

Kudos to the modders behind this: Revolution, assuming you've been playing "Portal 2" at expert level for 13 years, doesn't push you right into the deep end; in typical Valve fashion, Sterling's puzzles start small, while a full-voiced narration sets the stage. Find a portal gun that shoots only blue portals, throw some cubes at the buttons, and ride the elevator a lot.

Because of familiarity, the first chapter unfolds slowly and lasts a little longer than it takes to get your sea legs back. I had yet to get my hands on the orange portal button. In fact, I'm now in Chapter 4, and I still don't have it.

All of the puzzles so far have forced me to work with anchored orange portals, which I kind of like. It simplifies the puzzle because there is less freedom in the placement of the portals. It's much less overwhelming than vanilla Portal 2, and there are still no brain-melting moments where you're angrily blasting every wall in sight in hopes of finding the answer by accident. The restrictions have removed an important variable from the board, but the reduced authority over the portal creates a different kind of difficulty as the complexity increases in chapters 2 and 3.

And where I am now, things are really starting to get interesting. I am on the surface of Aperture Labs, portaling through a dilapidated exam room under a crisp blue sky. I didn't know Portal 2 could look so pretty. If Chelle had solved the puzzle in this situation, she would have .......

On the mechanical side, Revolution has finally incorporated more original elements. Blue and orange gels have been added to the mix, along with a new "cleansing" shower that instantly nullifies the effects of the gel and cleans the coated cubes. Most recently, I had to put orange gel on my cube in order to slide down a ramp, something I don't remember doing in Portal 2.

My only early complaint is the story. While it's fun to see Aperture from a new perspective, I don't think Sterling is the ideal traveling companion. So far, his dialogue is dry, his jokes are mostly rehashes of Portal 1's corpo-dystopian humor, and he doesn't put as much personality into his "personality core" as the Wheatleys did in Portal 2.

This may change when we reach the midpoint of Revolution, but if it doesn't I won't be disappointed. We were very impressed with Portal: not only for its quality and perfection as a mod, but as further evidence that Valve had a lot of meat on its bones with the Portal series. This is the Portal 2: Episode 1 we never got.

Portal: Portal: Revolution is free for Portal 2 owners, and is on sale for $0.99 for the next few days if you don't have Portal 2 for some reason.