New Editor interface,
Unity now supports third-party renderer materials
new Input System,
LTS releases focus entirely on stability and quality
2D tools make high-end 2D creation more accessible
Configurable Enter Play Mode
Upgraded the PhysX library from v3.4 to v4.1
See a detailed description of the release on the Unity website.
https://blogs.unity3d.com/2020/01/28/unity-2019-3-is-now-available/