Not sure if this is mentioned elsewhere, but if you run the game through ScummVM* instead of directly through the shortcut the installer places on your desktop, you can benefit from all the graphical smoothing etc. It looks sooooo much better.
* I know it's running through ScummVM already, but I mean if you /launch/ it through ScummVM

The filtering and scaling can be adjusted via keyboards shortcuts too:
'Ctrl' 'Alt' and '1-8' keys to select filtering
'Ctrl' 'Alt' and '+' or '-' keys to increase or decrease scaling.

...and the other ingame keyboard shortcuts (such as alt + enter for switching between windowed and fullscreen mode and music off with m) can be found from the README in the ScummVM folder.

Running Simon1 from ScummVM, you can also override 'speech' levels to be louder than music. It may help those who are having trouble hearing it, but don't want the non-talkie versoin subtitles.

Ois, you can change those settings from the ScummVM F6 menu while the game is running.
That menu also serves as a useful pause key :)

Youre not alone. F6 does nothing at all when pressed in Simon 1, and theres nothing wrong with my keyboard
according to Kirben (a scummvm developer iirc) F6 global menu isnt present in the latest stable version of scummvm used in these games.
seems to only exist in the beta versions of scummvm.