Is anyone else able to launch this game on Steam?

[Retropocalypse]

It refuses to launch.

After look at the Discussion page on Steam, I'm not alone. And the issue seems to extend to Aliens: Colonial Marines as well.

DRM problem, apparently.

[Still Collating...]

It is a problem for some. Steam screwed something up. There is a confirmed way to fix AvP. There are a few steps and a few possibilities, but one of them will work, just follow along the steps very closely. There's even a youtube tutorial of it now.

AvP Steam Forum Fix

There are a few options for A:CM as well, though we don't have it confirmed yet if all of those options work for A:CM as well, people are still troubleshooting and trying new things for it. But we know both are definitely fixable/savable.