To qualify to keep Until You Fall forever, you'll need to install and launch Until You Fall with an annual membership before the end of the promotional period. The campaign is available for both new and current annual members - monthly users can become eligible to receive Until You Fall during the promotion period by upgrading to an annual membership. Once you successfully download and launch Until You Fall, the game will remain available in your library indefinitely.
For more detail, please refer to https://www.viveport.com/infinity-until-you-fall