Godot 3.4 is a major new milestone with improvements all around, backported from the development branch of Godot 4.0, or written for the 3.x branch's specific needs. It includes reliable checks for object validity in release builds, large files support, rooms and portals-based occlusion culling, a new UI theme editor, glTF scene export, and more!
In case you encounter slow downloads on TuxFamily's servers, all files for this release are mirrored under Assets below.