Check out the details here: https://youtu.be/vKtTSUMgDjw
Blog post available here: http://blog.wolfire.com/2017/07/Overgrowth-Beta-4-video-changelog
Full change log is available here: https://docs.google.com/document/d/12tPguXp66gAWnuLhtvSFMcM24GrKrjqD6Th40bTimR0/edit?usp=sharing

Abridged Changelog:

Gameplay
- Made dogs no longer throw swords at you
- Added auto ledge grab feature (while pressing a direction) to make climbing simpler for new players
- Made dodge work a little better against knives (2nd attack doesn't get through now if you've timed your dodge correctly)
- Fixed some spawn points in magma arena that were causing character to fall through the world sometimes

Several improvements to new campaign

Graphics
- Added fog, moving water, and rainbow effects, and tweaked lighting in waterfall arena
- Added smoke and cinder particles and tweaked lighting in magma arena
- Added rain and gradient fog effects, and tweaked lighting in cave arena
- Preserve motion blur while pausing world for better screenshot angles
- Improvements to weather effects

Modding
- Revamped mod menu to make it much easier to see a bigger list of mods, and get a better preview area
- Added Disable All Mods button in mods menu to make it easier for players to debug problematic mods they've installed
- Added mod voting buttons to mods menu so mods get more votes (better feedback on mod quality)
- Added improved prefab support. You can now update the objects in the prefab and it update all levels it is used in, and maintain connections to other objects (weapons, dialogs, etc)
- Added search for objects by name in the scenegraph search, tagging objects with a name in the editor, filtering to only show named objects in scenegraph, and access to object names in angelscript
- Added scenegraph window and search hotkeys to editor ("Y", "CTRL + F")
- AI patrol path points can now trigger arbitrary animations instead of just Sit, Stand, etc
- Added progress unlocking to "simple campaign" mods, and hotspot so progress can be saved
- Added more parameters to nav mesh generation, to better control cases where small gaps aren't added to nav mesh
- Exposed Dear ImGui UI functions to mods

Sound
- Added ability to select preferred audio device, when default device isn't preferable
- Fixed some looped sound issues and playback stalls by switching to software mixing

Performance
- Pre-load most (if not all) assets for Lugaru campaign to reduce in-game content loads and hitching
- Improved loading speed of lugaru campaign menu
- Removed some sources of log spam, which should improve framerates in some cases

Many more reductions of CPU and GPU utilization

General improvements/bug fixes
- Put nav meshes in their own directory so it's harder to File -> Load a non-level file on accident
- Display list of mods when crashing so users know to try disabling them
- Fixed some bugs related to handling of IMPulseAlpha (should make some crash error messages more clear so we can debug them - won't fix the underlying crashes)
- Fixed some bugs where cursor disappeared when steam overlay is on
- Fixed some memory allocation and initialization issues
- Fixed some bugs when Steam Workshop APIs return errors

Known issues: Lugaru campaign progress saving isn’t working correctly on OSX. We plan to release a hotfix for this issue some time next week.

If you find any bugs, please email a full description along with your system specs to bugs@wolfire.com.