Valve has just released footage of the ice gun that would have been included in Half-Life 2: episode 3. It was described as 'kind of similar to a Silver Surfer' mode.

Half-Life 2’s third DLC was never completed because Gabe Newell, along with his team, wanted to do more than just finish the Half-Life 2 narrative arc. They also wanted to do something innovative and big in the game design. As Newell said in a recent documentary, he felt "stumped."

In the documentary released to celebrate Half-Life 2’s 20th anniversary there is also footage of some cool-looking Episode 3 content. This includes an ice-gun that can be used to create transparent barriers. But it also has a "kind of Silver Surfer mode", which lets you run along ice ramps while you are building them. This footage is the first I've seen of the ice gun.

The documentary's section on Episode 3 begins at around an hour and 53 minute mark. It's available on YouTube and I've queued up the video in the embedded player.

I guess I'm not Valve dev-material, because I would have been happy if they had released Episode 3 in 2010ish with the icegun and blobs. It wouldn't have been as amazing as Half-Life 2 Striders or Gravity Gun in 2004, but it would have had the ice gun and blobs. I would have loved it! Newell, in the documentary, said that it wasn't enough.

"You can't be lazy and say 'Oh, the story is moving forward'," he said. "That is a way to avoid your obligations to gamers. They love the story, yes. They love it in many different ways. You know, we could have shipped it, because it wouldn't be that difficult. I was unable to understand the failure, my own failure. "I couldn't understand why doing Episode 3 would push anything forward."

David Speyrer, an engineer at Valve, said that not everyone is in agreement: "We definitely could've gone back and spent another two years to create Episode 3."

But, hey! Who says the window is over? Half-Life 2 just got a major update to celebrate its 20th anniversary. Valve added a documentary and a bunch fixes, along with in-game commentary. It now includes Episodes 1, 2 and is free for limited time. Gabe might get that big idea one day.