Well, it starts up with a little chime (Hudson?) on start up, and a "pause" sound when you bring up the menu. The VC menu also has a completely different design with The PC Engine logo in the background.
In the menu you can bring up the Gamepad and TV settings separately. In each one you have Screen Mode: Default (4:3), Full (16:9 stretched), and Custom.
In custom you can manually adjust Vertical and horizontal position, screen size and screen ratio.
The emulation also seems to be very bright and clean looking (no filters), but I dunno, we probably need someone with a more discriminating eye to take a look at it.
Edit: Hmm, options for rapid fire buttons?