Uninstalling

# uninstall omegga
npm uninstall -g omegga

# remove omegga config
rm -rf ~/.config/omegga

# remove brickadia installs
rm -rf ~/.local/share/brickadia-launcher

# potentially remove extra brickadia config
rm ~/.config/Epic

~/.config/omegga is also where steamcmd installs the game, so removing it reclaims the Brickadia download too.

You will have to delete the server folders you created manually.

If you ran omegga in a container instead, none of the above applies: remove the container, its home volume, and the server directory you bind mounted. See Containers.