I've had this game downloaded for a while, is the steam build any different to 0.5? The one I have is complete, but I've always wondered why it was 0.5.
		
		
	 
Originally, the game versions were updated by a minor point for each chapter. There are five chapters, so the original final was 0.5. Then there was discussion about 1.0 being a more obvious final, and that was the next version defined when some bug fixes went out.
The Steam build is very different. It has an entirely different soundtrack due to the inability to get proper licensing from the performers/distributors. The Steam version has all the bug fixes done since it released on Steam last year. It has an upgraded Ren'Py engine, image- and replay galleries and a bunch of other minor improvements (including additional translation languages). There is also an official Walkthrough DLC for the Steam version that (unfortunately) is just not compatible with the Patreon/Itch versions.
An epilogue to resolve the Sadie Solo path cliffhanger is planned, but work has not commenced on that as of yet.