$ sudo apt-get remove freedoom 

Uninstall freedoom including dependent package

If you would like to remove freedoom and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove freedoom 

Use Purging freedoom

If you use with purge options to freedoom package all the configuration and dependent packages will be removed.

$ sudo apt-get purge freedoom 

If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.

$ sudo apt-get purge --auto-remove freedoom 

See Also,