Tonyx35: You need to launch/run the game by using the shortcut named "Aliens vs Predator Classic 2000 - Galaxy Client"
the first screenshot I attached shows you what shortcuts the Gog Installer created in the start menu.
"Aliens vs Predator Classic 2000" -shortcut will only run the Single Player and Multiplayer feature does not work A bit confusing because they use the same icon image.
The second screenshot that I have included shows what the launcher should look like.
If you ran the shortcut and the game automatically started, then that is the wrong shortcut. Exit back to desktop and try the other one.
RetroVGN: I launched both the AvP_Classic EXE, and the Shortcut in here, still no Multiplayer. I see an icon for the Launcher, but no Launcher. This is EXACTLY what I got in the GOG download after redeeming my code in the Screenshot below. I am getting super-livid here, as this game is REAAAALLLY old and should work by now, it's only 14 years later. If this is how GOG does with a BETA program, I don't wanna do the next one. Cool game, but faulty managing and programming.
Yo mate, the launcher is in the start menu, GOG.com submenu, AVP classic submenu, first icon. Not in the desktop nor game folder.
The shourtcut, points to another direcction with some commands, I guess you can create a shortcut anywhere and type in the following.
"C:\Program Files (x86)\GalaxyClient\GalaxyClient.exe" /gameId=1207665883 /command=launch /path="C:\GOG Games\AvP Classic"
That is if you installed the game in the default folder.
Cheers!