Sometimes, it's what outside of a level that's really interesting.

Portal 2's GLaDOS, the game's coolly sadistic robot narrator, wanted me to hate my co-op partner. In corporate lingo pulled from a dystopian HR manual, she warned that Portal 2's levels are lethal unless my teammate and I trust, respect and communicate with each other. "Naturally this will pose an interesting challenge for one of you," she said, "given the other's performance so far."

We might not be in the era of taking your PlayStation 4 to a shop down the street and getting a mod chip. But ever since Sony announced you could run Linux on the original PlayStation 3 - and subsequently removed it in future iterations - people have been keen on the idea of Linux running on the PS4.

But as a talk at the annual Chaos Communication Congress showed, the PS4 is definitely not a PC. And while that makes things harder, it doesn't mean you can't get Linux going on the PS4 nonetheless.

Doug "Rat Man" Rattmann is one of the most important characters in Portal, though he didn't appear in either game. The message-scrawling scientist made his video game debut in LEGO Dimensions' Portal level pack, though he's so well hidden it took more than a year to find him.

Any PC fan will tell you that mods can extend, improve or revive a game's prospects, and the ModDB repository is the home for just about every decent mod under the sun.

As is the case every year, the site nominates its top 100 mods and then opens the doors for fans to vote. But more importantly, it's a chance to catch up with some of the best mods from the last 12 months.

For all those cantankerous types who don't want other people to get cake.

Portal Stories: Mel was not made by Valve, but it's probably the closest thing we'll get to Portal 3 for a while.

With all those Thomas the Tank Engine mods for popular games, it's weird no one really went into LEGO territory yet. Andrewmfilms fills the gap with his awesomely animated clip featuring Portal 2, Counter-Strike, and Bioshock with minifigures.

There's been a couple of takes on shock-absorbing feet-tech in the Portal-verse. Now, someone's trying to make impact absorbing footwear for real.

Portal Stories: Mel, an upcoming mod for Portal 2, is starting to less like a mod in this new trailer, and more like a straight-up official Valve entry in the series.

We've featured Penny on Kotaku Australia before. First she helped her Dad — Australian game developer Lance E. McDonald — play Dark Souls II, then she started playing Portal 2 all by herself. Now she's finally managed to complete Portal 2. Quite an incredible achievement for a three year old!

Portal Stories: Mel is a mod for Portal 2 that has been three years in the making. With a whole new story, new gear and new missions, it will hopefully feel like a whole new Portal, only it's one you don't need to pay for.

A few months ago, we took a look at Aperture Tag, a Portal 2 mod that replaces the portal gun with a gun that can shoot the blue and orange gels to craft the levels into a bouncy, speedy wonderland. It's finally out and it's looking even better than before.

Briefly: Aperture Tag, the Portal 2 mod where you wield a Paint Gun instead of a Portal Gun, will be officially released on Steam this month. According to the developer's announcement, Aperture Tag will cost $US7, and will be sold at a 30 per cent discount during its first week.

You might remember Penny from her previous appearances on Kotaku. Previously she was helping her Dad (Australian game developer Lance E. McDonald) play, but now she's struck out on her own. Her first 'Let's Play' video is a humdinger: watch Penny play Portal 2 and feel your ovaries throb in response.

You may remember Lance E. McDonald is the creator of the upcoming game Black Annex, the modern game built completely in Basic, but Lance has now reinvented himself as a YouTube superstar. Actually, the real star is his three year old daughter Penny. Earlier this week they played Dark Souls II together and it was the cutest thing ever. Now they're playing Portal 2, or as his daughter calls it, 'ORDAL'!

Thinking With Time Machine is a new and grammatically dubious Portal 2 mod that lets you record and play back time loops to solve puzzles. Considering the trouble some people had with just the portals I'm imaging a few Scanner-style head pops here.

I was poking around for interesting Portal 2 maps to play, and instead found an entire mod that replaces the portal gun with a gun that shoots the blue and orange gel from Portal 2. Even better, it has an entire storyline with a new character.

Looks like Wheatley's space travels took him all the way to the Mun from Kerbal Space Program, with a little help from redditor Technotreese. Kerbals have quite the penchant for testing, so Wheatley should feel right at home.