At first I was stuck because I was being silly and clicking and dragging only on the blueprint area and wondering why nothing was happening. It was like only after a minute or so that I noticed the tiles in the black area to the right.
Nice puzzler! I was stuck because I didn't notice the directional arrows as well and thinking to myself that the lines all connect... did I have to press something to make the flow start? Then I understood why there was a need to Reflect tiles. I had to do much reflection myself :P
Congrats on the game's release!