The intro screen and the menus are new! How cool!
How do I fire and change weapon ? Space seems to not work.
It seems that the instructions are too well hidden... You have to select "Read This!" on the main menu and then click "Keyboard" to see what all the different keys do.
A sound daemon for symbos is for sure a priority. I would recommend a player for .afx files that for Ay8910 are pretty simple and wide spread. There are editors and libraries for them.
What are the sound chips of the other systems supported by symbos?