Portal with RTX review: Ray tracing makes Valve’s puzzle FPS spooky

Can a remaster change a video game’s genre? After a couple of hours with Portal’s free ray-tracing update, I’m tempted to say yes.

The original Portal is on the short list for “funniest video games ever made.” Released in 2007 as a spinoff of Half-Life, this bite-sized first-person puzzle game grabbed the humor from its parent series and yanked it from the periphery into the spotlight. You play as Chell, a human lab rat, who gradually outsmarts a malevolent artificial intelligence named GLaDOS who talks like Siri by way of Mitch Hedberg. You use little more than your wits, Chell’s physical fitness, and a nonlethal “gun” that, instead of bullets, shoots a pair of interconnected portals. It’s as thrilling as it is cartoonish, best remembered for a cake meme and its closing credits pop song written by humorist musician Jonathan Coulton.

Portal with RTX is, in everything but the visuals, the same game. The same puzzles, the same script and voice acting, the same dessert reference and endgame ditty. Except it looks different. To make the most of the latest high-end graphics cards, GPU maker Nvidia has partnered with Portal’s publisher, Valve, to create an updated variant transmogrified by the graphical wizardry of the moment: ray tracing.

What is ray tracing? Well, how much time do you have? If you have 20 minutes, I strongly encourage you to watch this breakdown from the experts at Digital Foundry. However, if you only have a few seconds, here’s the elevator pitch. Ray tracing is a considerably more realistic method for simulating light in video games. With ray tracing, you will see reflections and shadows, along with representations of the tiny ways that light can bounce off, bend through, and absorb into materials.

Ray tracing is particularly noticeable in environments where light itself is most noticeable: wet surfaces, reflective metals, glass, and mirrors. Portal’s labyrinth of industrial test chambers is a natural fit.

In terms of making an exceptionally realistic laboratory, the creative team for Portal with RTX has created a version of Portal that prioritizes realism above all else. Assuming you can get the thing to run — it took an Nvidia RTX 3090 with Deep Learning Super Sampling enabled to get something close to reliable performance on a 4K TV — you will see a frighteningly believable version of GLaDOS’ laboratory. And I do mean frightening.

Image: Lightspeed Studios/Nvidia via Polygon

To emphasize the dynamic lighting, Portal’s laboratory with RTX is darker and moodier; inky shadows fill every corner. Many surfaces now appear wet and icky, like if you scraped your knee you’d contract some rare bacterial infection. Balls of electricity bounce about, casting a soft, ghostly light. The walls don’t just look like metal paneling; they look like heavy, immovable blocks of steel. The result is far more claustrophobic.

We’ve seen a similar effect in other classic games that have received ray-tracing updates. With natural light in place of artificial light, things tend to get a bit dark and spooky. But the addition of ray tracing has never skewed so closely toward horror as in Portal with RTX. In this case, it’s not just that the game is darker — there are still plenty of rooms with sickly office fluorescent lighting. By emphasizing realism in the visuals, Portal’s entire vibe has shifted from cartoonish to something much more sinister.

Valve’s video games from the 2000s have an iconic blocky, grimy, and muted aesthetic, which ends up flattering the corpo-fascist art direction of its first-person shooters. While other AAA shooters of the era like Crysis and Call of Duty served as technical showpieces that prioritized raw horsepower, the Half-Life series emphasized art direction. Valve’s worlds weren’t as technically impressive, but they were more considered. The look served a function.

Image: Lightspeed Studios/Nvidia via Polygon

In the case of Portal, that function was fun and humor. Yes, you play as a human lab rat, but success never really feels out of the question. It was the closest Valve had come to making a family-friendly game, with no lethal weapons or human targets. And Valve’s blocky aesthetic set a clear divide between the real world and the video game. GLaDOS’ increasingly heightened, malevolent monologue popped perfectly against the background of bland, abandoned labs.

But in these eerie chambers of Portal with RTX, GLaDOS immediately sounds more menacing. The big red glass buttons, the Companion Cubes, and the looming viewing chambers used to feel rather silly — but not so much anymore. Now, they’re set-pieces in a corporate haunted house. The result is a different experience from playing Portal 15 years ago.

Portal with RTX isn’t Portal, not truly. It’s something else, an alternate vision that feels a bit closer to Half-Life 2’s Ravenholm. You might find the visual upgrade unsettling, especially if you’re more of an originalist who likes things as they were “meant to be.” Or, you might be excited by revisiting Portal through a more menacing lens.

Image: Lightspeed Studios/Nvidia via Polygon

Or, if you’re the sort of person obsessed with the future of video game visuals, you will appreciate Portal’s RTX update for what it does best: Prove that ray tracing matters. Ray tracing’s ability to significantly alter the game’s mood captures something powerful about the technology that can’t be seen in screenshots or a tech demo video on YouTube.

If ray tracing can have this sort of impact on a game that was never meant to have it, imagine what artists will do when incorporating the feature from the very beginning.

Portal with RTX launches on Dec. 8 on Windows PC and requires high-end system specifications. The game was reviewed on PC using a pre-release download code provided by Nvidia. Vox Media has affiliate partnerships. These do not influence editorial content, though Vox Media may earn commissions for products purchased via affiliate links. You can find additional information about Polygon’s ethics policy here.