Update: Desktop user interface
So as I said earlier, this game takes place in a Unix-like operating system. Well, here's the desktop environment of said operating system.
It's very work-in-progress and I haven't uploaded a demo video of it yet, but I really like it so far. It's based off of the GNOME 2/MATE user interface with a bit of KWin thrown in with the window borders. The two panels (at the top and at the bottom) allow you to open programs, see minimal system status, and switch between windows. (Most of that hasn't been implemented yet. Anything you click in the "Peacegate" menu just opens a "You clicked a menu item!" dialog.)
The little computer monitor icon at the left of the bottom bar is a "Show desktop" button. Much like the one in real MATE, clicking it either hides all windows or brings them back onto the screen.
Support for multiple desktops, as well as movable desktop widgets is coming, though not in the Jan 2018 prealpha.