I believe many of the "timed limited" demos of Steam Game Festival have reappeared as permanent demos. For instance I checked Haven and whilst there's no button to add the demo I could add it via steamdb free packages script.
		
		
	
	
		
	
I haven't tried to run the demo but I suppose it should work.
				
			
	I haven't tried to run the demo but I suppose it should work.
		Reason: better readability + demo license
	
										
										
											
	
										
									
								
				
		


	
	
	

	


	
	