Interacting with your Pixel
The pixel has 6 buttons on the back side: the 4 directional ones you use with your left hand, and A/B with your right. A is used for accepting/continuing, and B for declining/stopping. All apps by default will exit when you press B.
Launcher
The badge boots into a launcher application, from which you can run all the apps you’ve installed with the up/down buttons. A starts the selected app.
You can remove any app that you install through the app store by pressing B in the launcher. System apps are protected from removal. Source code of these system apps can be found on Github.
In the launcher you can adjust the brightness of the display with the left/right buttons. You might want to decrease the brightness a bit now, as the Pixel ships with maximum brightness configured.. :)