Actually that depends whether you're using a database file associated to your romset...or not!
If you don't use a database file, mGalaxy lists the roms as they are named and: no, you can't!!
If you're using a database: yes, you can!
It's just a matter of editing the 'xmlout.xml' file (the database file) and modifying the description tag.
<game name="10yard" cloneof="">
<description>10-Yard Fight (World, set 1)</description>
<genre>Sports / Football Amer.</genre>
<players>2P alt</players>
</game>
You're not using a database file..but would like to do so to fix your problem?
- Download an already existing one there:
http://www.mgalaxy.com/forum/index.php?action=downloads;cat=1- Create your own one with the help of mGalaxy_Runway (sse picture > "Create database" button)
- Use an app called RomLister to generate your database (RomLister can output to mGalaxy database format!)
Don't forget to check the "Use database file.." checkbox in mGalaxy_Runway too!
Hope it'll help!!