Aliens vs Predator Classic 2000, (the good one) a suspenseful Sci-Fi first-person shooter with three very different single-player campaigns, one for each species, and a frantic multiplayer mode, is available for FREE for 48 hours on GOG.com
httpv://www.youtube.com/watch?v=BsLPOiYzFPA
HOW TO GET YOUR KEY:
1. Sign up for GOG Galaxy beta tests
2. Wait for an e-mail with your activation code (it will be sent to you within the next few days)
3. S#%t your pants when playing the Marine campaign
Important: You need to sign up before Friday, October 17, at 9:59AM GMT.