So I like to play a game in full-screen mode while watching Netflix on a small window.
No, as far as I do not know, however, you can turn off in full view as well as any game under graphic settings or minimize the picture.
You could connect a second monitor via an HDMI cable and then on Windows 10 press the following keys: "Windows + Shift + Left" for the left screen
"Windows + Shift + Right" for the right screen.
Alternatively, if you have the monitor connected to your PC, a window should appear on the right side of your output monitor. There you click on "Advanced" and can thus push the windows on the second screen.
This does not work if an application is in full screen mode (at least up to Windows 8.1).
Perhaps OnTopReplica is an exception, but only if it does not use the usual Windows graphical interfaces.