I couldn't finish level 3. I had 33/33 resistance and the path was fully connected from input to output. I tried a few other paths that also had 33/33 and were fully connected, no luck. Picture for reference MaybeBug.png
Regardless, it is a good puzzle game concept. There are a few small presentation issues that if fixed would go a long way in making the game easier to play. There needs to be some way of knowing which piece is selected, maybe just putting a highlight around the selected one would be all that's needed. Adding the resistance value for each piece without having to click on it would also help a lot. But the concept has a lot of potential and I can see a lot of ways to make more complex puzzles.