Ah really glad you enjoyed it mate, and this feedback is really helpful, gives me the drive to keep working on it!
I totally forgot to give any tutorial on the Raw Materials concept. The idea is every building you place is classed as one of three stages in the thought "production line"; Raw Materials, Refinery and Storage. Then the adjacency puzzles will get more complicated by using those as requirements. But then I didn't put any explanation besides the small icons in the tooltip window - definitely something for the next version.
Completely agree the actual first puzzle will need to be simpler and introduce each building one by one. That, some SFX, music, and background art are next on the cards (after fixing the damn inventory glitch).
On the blurriness, I noticed this as well, I made it in Gamemaker and just went in to check the settings; pixel interpolation was on so unchecking that helps there.
Again, thanks so much for taking the time to give feedback, going to try to turn this into something!