Return to Aperture in the crossfire of Portal's ending, and see how everything changes in Portal: Catalyst, a free modification based on the vanilla Portal 2 engine. With a power-vacuum opened up in the Enrichment Center, only two questions remain; what ancient programs are keeping this facility going long beyond the Central AI's downfall? And how are you going to escape?

Portal: Catalyst seeks to explore Aperture's transitional period between the two games, showing the facility changing from the iconic aesthetic in the first Portal game, and transforming it into the sci-fi madhouse of the sequel.

Portal: Catalyst is planned to contain:

  • A full singleplayer campaign with a unique story for casual and devoted Portal fans alike.
  • Many new and fresh Test Chambers to keep you thinking and puzzled.
  • The return of the infamous High Energy Pellet, with a new accompanying element for further interaction.
  • New, fresh, and reimagined characters to meet in Aperture.
  • A new spin on a classic formula of an antagonist.
  • New takes on familiar environments.
  • And a completely new soundtrack!

Portal: Catalyst is still early in development, and we would appreciate all the help we could get! Please contact us on our Discord for any questions you might have.

Join The Official Discord Server: Discord.gg
We provide updates and you can communicate directly with the team!

Despite intending to maintain the spirit of Conversion/Mind Escape, Catalyst does not contain any elements of story from the previous mods, Catalyst will be an entirely fresh experience.

  • View media
  • View media
  • View media
  • View media
  • View media
  • View media
RSS Articles

Hello everyone, Ossy Flawol here, lead developer of Portal: Catalyst, and man, what a crazy year it’s been!

As is tradition, we commemorate the anniversary of Catalyst’s development starting on October 11th, 2019. This time around, we’re celebrating it by bringing you our third, and biggest major update on progress, coinciding with our third year of development!

There’s a lot to unpack with what we’ve been doing over the past year of development, and especially since our Refurbishment Showcase earlier this year. So without further ado, let’s begin to answer the question — what was Catalyst up to in the past few months?

One of the very first goals that was pitched and set in-stone for Catalyst was a simple one — the visual identity of the original Portal needed a makeover, and we were gonna give it one. This wasn’t due to simply wanting to remake the assets because we could, but more a choice influenced by art direction.

A key aspect of Catalyst’s identity is its usage of the classic industrial Aperture look from the first Portal game, as we aim to bridge the gap between the grounded aesthetic of Portal and show how the facility transitions towards Portal 2’s sci-fi look. While the transition is not something that is the forefront of the story, it is something that you still will see actively play out.

Yes, we are well aware that the actual reason the two games look so different is due to the new art direction that Portal 2 takes, but bridging the Portal duology’s looks has created an incredibly fascinating setting for a story we can tell, and this involves the two Aperture aesthetics intermingling. So before anything further, let’s talk a little about art direction.

The original Portal has a more grounded look to it because it was a game built from the aesthetic basis of Half Life 2. It was a project headed by freshly graduated students who did not have the development resources to create their own look for Portal, meaning that it was smart to build on what was seen in Half-Life 2. It was efficient resource-wise and allowed for reusing what they could from that game. However, come Portal 2, and you’ve got the entirety of Valve working on it. With a whole company comes a whole new art direction, especially one that looks a little awkward when placed right next to the original Portal.

So, in a process that took us a year and then some, we’ve been upgrading the look of Portal to faithfully match the art direction of Portal 2. Many assets were created in this task, done by members both currently and formerly on the team, and even community-created assets that we have seen fit to use. I would like to thank all the people on the team who made this possible!

  • Distanced
  • Frosti
  • Valla-Chan
  • November
  • Arienne

We’d also like to shout out Adakam, a former developer of ours, for her redone Observation Room wall textures. Alongside a special thanks to Erin-Rose for their modelled piston assets, and even the developers of Conversion/Mind Escape for permission to use models from the mod, both of which have found use in Catalyst!

Valla-Chan has also allowed us permission to utilise content from her faithful Portal remaster project — Every Last Crumb. Catalyst’s upgrade effort is still an ongoing process, as some assets still require remasters, and some might even change still, but we’re at a point now where we can comfortably showcase our environments from Chapter 1 and 3. Now, let’s show off some of these remade assets properly!

The team is very proud of how it’s been turning out, as our aim was to be faithful to the original Portal aesthetic, while still bridging it closer towards Portal 2’s look and identity. Now, to form a complete picture, check out the video below for a gameplay demo from one of our Chapter 1 puzzles! You can see how wonderfully this work all integrates together here.

Oh, but that’s not all…

That’s right, I said Chapters 1 and 3.

One of Catalyst’s key story traits is that you are placed literally right in the crossfire of Portal’s ending, with the mod starting mere minutes before Chell delivers the final blow that shuts down GLaDOS. This isn't just a piece of technology failing, the very core of Aperture Science itself has been destroyed, and the facility is in full panic mode.

Automated systems now ring out across Aperture Science, alarms sound, and evacuation alerts informing everyone to get to safety blare throughout the facility — with, of course, no one to hear it. The destruction of the Central Core was such an unprecedented scenario, that the facility has entered Disaster Response Mode, believing a major earthquake has shaken Aperture Science.

Chapters 2 and 3 take place in this apocalyptic circumstance. You are not witnessing the decayed carcass of Aperture Science, you are stuck in the middle of it falling apart. The puzzles you solve here are barely functional, clinging to the last bits of power they can utilise. It may be dangerous, but it’s safer to be in the Test Track than the electrical inferno of the industrial backstage.

Gameplay wise, Chapter 3 introduces the High Energy Ring, our new Test Element we’ve created for use in conjunction with the iconic and classic High Energy Pellets from Portal. Alongside this, we’ve also been working to make the Energy Pellet a more reliable Test Element to work with, and as a result, you’ll be seeing these for the majority of Catalyst’s gameplay:

This is an Infinite Pellet, simply an Energy Pellet with a never-ending lifespan. It can be reset via input into the launcher. Due to its incredibly limited usage in the first Portal, we’ve seen it to be perfectly fine to update its original green colour. Now, it matches the blue/orange colour scheme seen in Test Elements in Portal 2.

The usage of Infinite Pellets in conjunction with the High Energy Ring has created some incredibly clever puzzles that cannot be done with any other Test Element, showing that this orb of energy still has a place in puzzles alongside Portal 2’s replacements for them. (The lasers, of course.)

One of the unique puzzle moves that have come from the Infinite Pellet is something we’ve dubbed the “Storage” move, wherein an Energy Pellet can be reserved for later use in a puzzle. To demonstrate this, here’s a second gameplay demo, showcasing the puzzle that introduces this manoeuvre!

We’ll be uploading an OST video for the music heard in this showcase, “Concrete Furnace”, at a later date! Concrete Furnace was composed by Mikeastro, our main puzzle designer and secondary musician.


High Energy Pellets have also been greatly improved on the backend of things thanks to the Source Engine’s ever-powerful VScript systems. With some incredible tinkering, TeamSpen210 has made Pellets a more consistent Test Element to work with.

As an example, High Energy Pellets will now generate Placement Helpers (or ‘Portal Magnets’, as they’re more commonly called by BEEMod users) wherever they’re about to land, making Pellets more consistently pass through the centre of portals. This brings Energy Pellets more in line with Portal 2’s cast of test elements, as they all also generate their own Placement Helpers to aid the player’s portal shots.

High Energy Rings have also received a small upgrade in this regard, as Energy Pellets will now be teleported to the centre of the ring when passing through the hole. Making these volatile balls of energy more easy to manage in puzzles hasmade them much more satisfying as a Test Element, and we hope to continue streamlining this iconic element.

Our crazy little development map where TeamSpen210 works his magic on the Energy Pellets.

Of course, Chapters 1 and 3’s puzzles aren’t the only thing we’ve been working on! Earlier this year, we finished the art pass on Chapter 5’s puzzles, our Modern Aperture chapter that introduces the Excursion Funnel, Repulsion Gel, and Propulsion Gel. We released a few screenshots a while back, but here’s a little more!

The maps seen here were done by Ossy Flawol (me!), TeamSpen210, and November, but let’s not forget the main attraction of the article here, here’s some more Chapter 1 and 3 images!


And the puzzles done here were by Mesos, Ossy Flawol (me again!), and Person Meetup! The synergy on the team to get this all art passed was absolutely crazy, and super motivating for everyone involved, let’s not forget about Refurbishment, our Chapter 4 theme, here too!

These maps were done by Rai and Mesos respectively, and Chapter 4’s puzzles are nearing art-pass completion themselves!

As we sit in the 10th month of this year, we look forward to 2023 and the years beyond. Catalyst still has some ways to go, but we’re beginning to reach a point where more than half the content of the mod has been created. With Chapters 1 and 5 having been fully art passed, alongside Chapters 3 and 4 soon to follow, we’ll only have one chapter worth of puzzles left to make, which will be our biggest yet.

We expect to have all our puzzles fully art passed sometime in early to mid 2023, and many eyes in the team are looking towards the next parts of our internal roadmap. Currently, we are on Phase 2, while the final puzzle related chapter is Phase 3. We’ll be entering Phase 4 of the internal roadmap before we even know it—which is when we’ll begin implementing story related content into Catalyst.

Our internal development spreadsheet for organising all the puzzle-focused maps in Catalyst.

Currently, the team is 17 people strong, but B-Name Studios is still openly looking for new volunteers to join the team! We are looking for people who can fill these 2 positions in particular:


  • Catalyst is in need of more asset creation people, especially once it comes to story related models! While most of our story will be perfectly fine, there are some that require certain hero assets to be made, such as, for example, a model for our protagonist.
  • We’re also still deep into overhauling Portal 1’s look, and there are a lot of models that’ll need to be made, so assistance with this is needed!

Voice Actors

  • We are officially looking for Voice Actors! Arienne, a new member of the team, joined the team to breathe life into one of our three major new characters, and her work in bringing them to reality has been amazing!
  • Catalyst is specifically looking for:
    • A male voice actor who is assertive in tone; this character believes themselves to always be right with full confidence, yet is mad when proven wrong. They’ll be accomplishing tasks consistently the wrong way, and telling themselves that they’re the best at it, all with just a small bit of vitriol towards the player.
    • A second male voice actor who can perform a more androgynous and calming tone, but not afraid to become the dominant voice in situations when required. This character sticks close to the player throughout the events of Catalyst, and is integral to the plot. A typical sidekick, but one that can stand on his own when the time calls for it.

Of course, we have a wide variety of other positions available too, so consider applying to join us in the development of Portal: Catalyst! Forms.gle

With that, this marks the end of our showcase! Progress on Phase 2 of development should be wrapping up before you even know it, marking a half-way point in Catalyst’s progress. The team is at a point where we are very motivated, and it is almost certain that we will be seeing Portal: Catalyst through to the end and be finished.

I thank everyone for patiently waiting and supporting this mod for the past 3 years, and I hope that we can make Portal: Catalyst worth the wait. B-Name Studios will be returning to work on our next few phases of development, which we should hopefully be blasting through with speed!

Thank you all for tuning into this progress update, we'll have more coming soon. :)

- Ossy Flawol, Lead Developer of Portal: Catalyst

Refurbishment Showcase - Development Update #2

Refurbishment Showcase - Development Update #2

News 3 comments

Join us in this article as we go over the new Refurbishment style featured in Chapter 4 of Catalyst, showing off gameplay for the very first time and...

Catalyst's First Development Anniversary is Here!

Catalyst's First Development Anniversary is Here!

News 8 comments

Come join us as we recap on everything that's occured over the past year of development, and as we reveal new exciting announcements!

Comments  (0 - 10 of 39)
SangheiliosThel - - 39 comments

Very fun mod premise. It'll be cool to see P1 and P2s aesthetics intermingled.

Out of curiosity, are P1s Cubes larger than P2s in the original games or is that just an illusion of the two games presentation being slightly different? And will the mod take that into account?

Also will P1 movement be an option? Since that's one of my most anticipated features of P2CE and this mod is built off of that.

Either way, looking forward to it.

Reply Good karma Bad karma+2 votes
OssyFlawol Creator
OssyFlawol - - 23 comments

This mod is not built off of P2:CE as of 2020 and has remained this way for years. P2:CE itself is still missing the P1 movement options to begin with, we have been working off of default Portal 2's engine instead.

Reply Good karma+3 votes
loshara555 - - 2 comments


Reply Good karma Bad karma+1 vote
arthurpanema - - 12 comments

It Will be interesting How you guys Will explain ART therapy but looking forward to the mod, good luck!

Reply Good karma Bad karma+1 vote
maxkatzurmaxim - - 273 comments

From the creators of Portal: Epic Edition comes this Conversion-inspired thing.

Reply Good karma Bad karma+2 votes
oyqea-ntrtaynmnt-llc - - 164 comments

No kidding.

Reply Good karma Bad karma+2 votes
OssyFlawol Creator
OssyFlawol - - 23 comments

Portal Epic Edition was just a fun little project I did to relieve some stress while working on Catalyst, Portal Epic Edition at this point is handled by it's own development team seperately from me.

Reply Good karma+2 votes
maxkatzurmaxim - - 273 comments

This mod is an glorious fever dream, though.

Reply Good karma Bad karma+1 vote
kakhaeziorashya16 - - 75 comments

Uh.. Any updates?

Reply Good karma Bad karma0 votes
OssyFlawol Creator
OssyFlawol - - 23 comments

We're still alive, don't worry! We're getting closer to getting our new showcase out :)

Reply Good karma+2 votes
Post a comment
Sign in or join with:

Only registered members can share their thoughts. So come on! Join the community today (totally free - or sign in with your social account on the right) and join in the conversation.


Latest posts from @catalystmod

Happy Holidays! The Enrichment Center may be tearing itself apart at the seams over here, but the Crew is here to… T.co

Dec 25 2022

As the date strikes October 11th this year, Portal: Catalyst is now 3 years into development. Read up on what we’ve… T.co

Oct 10 2022

Happy 15th Anniversary, #Portal! To celebrate the occasion, we’re releasing a video early for Portal’s special day,… T.co

Oct 9 2022


Oct 7 2022

Mark the date, Portal: Catalyst is back with a new major development showcase on October 11th, 2022. T.co

Sep 14 2022

Interested in hearing the full track seen in our Gameplay Teaser? You can listen to 1.1 Volts, composed by… T.co

Feb 13 2022

Watch the Gameplay Teaser for Portal: Catalyst, now live on YouTube! - Youtu.be T.co

Feb 13 2022

The premiere starts in 1 Hour! Tune in for your very first look at Catalyst, it's OST, and following the premiere,… T.co

Feb 12 2022

...Because something exciting is on the horizon. Tune in for the Premiere of our Gameplay Teaser, set to start in… T.co

Feb 12 2022


Portal: Catalyst has not been tagged yet.