I don't think so.

Source : https://discussions.unity.com/t/can-i-distribute-unitys-dll-with-an-open-source-project/218013.

No, you can not. The UnityEngine.dll and other modules are part of the Unity engine. They can be distributed with a game build with the Unity engine. You are no allowed to use of distribute parts of the engine outside a Unity project.

Apart from that most things you find inside the UnityEngine.dll requires the native core of the Unity engine as many parts of the UnityEngine.dll are just wrapper classes which refer to externally defined methods. This is not only true for the various component classes but also parts of the strucs (like Vector2/3/4, Matrix4x4, Quaternion, …).

I don’t think there’s anything inside the UnityEngine.dll that would be worth using outside of Unity. If it’s something simple it’s probably easier to implement the functionality yourself. If it’s more complex it most likely depends on the engine core anyways. What exatly are you using from those assemblies?

Said by Bunny83