Here's a bunch, in no particular order:

https://godotengine.org/

https://o3de.org/

https://defold.com/

https://www.stride3d.net/

https://gdevelop.io/

https://armory3d.org/

https://torque3d.org/engine/

https://flaxengine.com/

https://pragma-engine.com/

https://wickedengine.net/

https://www.adventuregamestudio.co.uk/

https://castle-engine.io/

https://solarus-games.org/