Valve announced today that all Half-Life games are now free through the March release of the VR spinoff Alyx.

“Half-Life: Alyx is coming in March, and we are celebrating early by making all games in the Half-Life series FREE to play for Steam users, from now until the day it launches,” the Valve announcement notes. “Half-Life: Alyx is set before the events of Half-Life 2 and the episodes, but the games share characters and story elements. The Half-Life: Alyx team believes that the best way to enjoy the new game is to play through the old ones, especially Half-Life 2 and the episodes, so we want to make that as easy as possible.”

Whether you’ve played these games or not, I can highly recommend putting aside some time to play them (again) now. All of them are excellent, including the two Half-Life spin-offs—Opposing Force and Blue Shift, both of which were made by Gearbox—which don’t appear to be part of this promotion. But the games that are available for free play are for on PC only, and require the Steam client.

Once you have that, you can download each game using these links:

Half-Life
Half-Life 2
Half-Life 2: Episode One
Half-Life 2: Episode Two