- Paint 3D is essentially Microsoft Paint in UWP with a proper graphics library. It has 3D graphics you can paint on with different brushes and add on top of 2D pictures. It also has a social media dedicated to sharing 3D designs (which is oddly separated from http://www.docs.com.
- New app that lets you view 3D models.
- A bunch of apps related to Windows Mixed Reality are in the update, including the one you use to set headsets up.
- Edge improvements: Set-aside tabs, EPUB support, More extensions, better rendering engine, new start page, tap-to-run flash.
- Themes: In the settings app, under personalization you get themes. No, its not classic/aero, it's a link to the store where you can install desktop background and sound packs. Also, custom accent colors.
- Night light: Its official! f.lux has been sherlocked, and there's a nice button for it in the Action Center.
- Game Bar improvements, including Game Mode, built in Beam broadcasting, and 60fps recordings.
- New picture in picture API (which deprecates snap on XBOX)
(just imagine this in the corner of your screen)
- New start menu mode similar to Windows Mobile.
I probably missed a bunch of things. If you have any questions, I'm here!