Here’s an excuse to play Half-Life 2 again.

Gaming hardware and peripheral maker Razer announced today that several SteamVR games, including popular hits like Half-Life 2 and Team Fortress 2, are now available to play in virtual reality via OSVR, an open VR software and hardware platform. Users can play OSVR games with the Hacker Development Kit, a headset that costs $300 (which is cheaper than the preorder price for the $600 Oculus Rift and the $800 price of the HTC Vive, which is backed by Valve). Tech adviser Digi-Capital predicts that the virtual and augmented reality markets could grow to $120 billion in revenue by 2020, and having classic games like these available in VR can attract skeptical consumers.

Both Half-Life 2 and Team Fortress 2 are first-person shooters from developer Valve. Half-Life 2 is a single-player adventure, and some consider it as the best game ever made. Team Fortress 2 focuses on team-based competition. Both are older games, but have remained popular with PC gamers. The first-person perspective will help them work well in VR.

“The Hacker Development Kit is designed to be a balance between quality and system requirements, allowing for enjoyment of VR experiences on mid-tier gaming PCs or better,” Razer noted in a press release sent to GamesBeat. “For those with hardware enthusiast/developer level of proficiency, it is also upgradable to get the VR experience you want.”

The spaces-based Elite: Dangerous, racer Live for Speed, and Spermination (I’ll let you guess what that one’s about) are also now available in OSVR.