Project Borealis is a fan-made Half-Life 2: Episode 3 based on the Epistle 3 script posted by former Valve writer Marc Laidlaw. It's been in development since 2017, and today the team showcased the first footage of some new maps, along with a shootout with some creepy homunculi still awaiting their textures.

The update explores the level design process, showing off a chilly cave's development from a section of a script to an in-game map that's had its first art pass. We also get to see some of the progress the team's made with the episode's physics, and it's going to be switching to the new Unreal Chaos Physics system and AMD's FEM deformation tool when they're released, but they've already been doing a lot of experimenting with PhysX.

The gravity gun has received a pretty significant upgrade. Instead of just picking up individual objects, it will be able to gather up lots of them, and the demo lets Gordon create a huge floating mass made up from hundreds of objects. I look forward to summoning tornadoes.

OK, that's pretty cool, but that's got nothing on this adorable headcrab. It's fluffy! Because it's cold! Let's hope we can pet the headcrab. Expect to see familiar but slightly different alien nasties in Antarctica, and some new stuff, too, including a vehicle to help us get around the frozen wasteland.

The team's also been working on the audio design, using Steam Audio to handle reverb, occlusion and spacialisation, and new art has been designed that interprets the low resolution models from Half-Life 2 and creates more detailed versions of them that still look authentic. That process starts with creating concept art for things like Combine panels, and a bunch of new concept art has been added to the official site.

"This update is the result of a significant evolution in the team over the last year," says project manager Florian Häsler. "We refined our development workflows and adopted a new approach to structuring the work ahead of us. This has brought about great work, some of which we’re showcasing in this update; the team is developing some exciting tech, using modern technology to explore our gameplay options. We can’t wait to hear what the community thinks about our progress and direction."

Laidlaw's synopsis sent Freeman, or "Freemont", off to Antarctica, where he ends up on the Aperture Science ship, the Borealis. There are some problems with reality getting a bit wobbly, culminating in a big fight on a ship that's speeding across time and space. You can read the whole thing here. It's pretty wild.