Keep an eye on Steam; while rarely free-to-keep, it often sees deep discounts (up to 75% off) during seasonal sales. System Requirements (PC)

As you complete missions, you unlock new abilities and hidden areas in each level. How to Play (Free Options & Access)

If you are a subscriber to Xbox Game Pass (PC or Console), Rush is included in the library. You can download and play the full game at no extra cost as part of your membership.