If you've accidentally zoomed in or out on the Amazing Marvin desktop app, you can easily reset or adjust the view. Here's how:
Press the Alt key to reveal the app's menu bar (on Windows and Linux)
Click on the "View" tab in the menu bar:
You'll see three options:
Actual size: Click this to reset the zoom to the default level
Zoom in: Click this to increase the UI scale
Zoom out: Click this to decrease the UI scale
You can also press Ctrl+0 to reset the view, without having to open the menu bar.