PhyreEngine™ is a complete high performance multi-platform game engine, offering quick and easy development for both rapid prototyping and full production. The entire engine is provided as source making it easily customisable to meet your needs. It’s completely free to registered developers and licensed for usage on any platform. Used in over 200+ titles across a number of different of platforms, PhyreEngine™ has been successfully adopted by dozens of game studios around the world.
As the blurb says, multiple titles use this engine from Sony Interactive Entertainment, including Final Fantasy X/X-2 HD Remaster, OlliOlli 2, Gunslugs, and Dragon Quest Builders.