Graphics options and Input Rebinding can now be done from in-game, so the Unity Launcher has been removed.
The Unity Splash Screen has also been removed. Slime Research now starts instantly, if you disable the Early Access splash (and adorable Dr. K animation) from the graphics options.

The new Audio menu lets you control volumes for Master, Slime, Objects, and Music. You can view the currently playing song from the audio menu, and new songs no longer appear as popups.
The new Graphics menu allows you to choose from any supported resolution, and toggle between fullscreen and windowed mode.
The Input menu is unchanged, and allows you to independently enable and edit inputs for Keyboard, Gamepad, and Mouse-Only.

All of your settings are saved to Steam Cloud along with your custom levels and completed levels.

If you have any feedback or experience any problems with these changes, please tell me!