How do I remove a game off steam that doesn't give the the option when I right click

The game "No more room in hell" will not show the option to remove when I right click on it. I installed the game through Desura quite some time ago and it put it in my steam library but now I want it out of there. Any idea of how I can do that?

Solution 1:

Since it's a mod residing in Steam's steamapps\sourcemods folders (see here), either delete that folder (probably nmrih, automatically also removing the Steam entry) or use Desura again to uninstall it there, which also should remove the Steam entry and folder.

In case the folder cannot be entirely deleted despite Steam being closed (e.g. Windows may claim you need Administrator permissions even though you have them), use the tool unlocker. Thanks @galacitninja for mentioning that