Sometimes, it just gets on a black screen after beating a level. It's good otherwise, but that's a big drawback.

Very good, with only a few minor snags:

1. The instructions could be a little more complete, like telling you the goal in the first level (you can work it out, but it helps to be clear), or explaining restrictions like how you can't connect power to a node that already has power.
2. Allow to chain-drag across nodes for smoother play, rather than having to release and click one by one when you want to connect a few in a row.
3. Allow stepping straight to the next level rather than having to return to the level select to pick the next one.

They're not major faults, but they make playing feel slightly awkward.

This actually really got me thinking. Which doesn't happen a lot.

Great game, smart mechanics, kinda reminds me of one of those puzzle games from coolmathgames 9/10