Games Magazine awarded it as the Puzzle of the Year in 2013. This game's been on my mind for 5 years! But I've finally gotten around to it.
I've tackled 27 of the 40 levels. Multiple times I peeked at the solutions to get a hint.
There is a sequel called Cool Circuits Over the top. Which mysteriously is not on the company website. I have the game but have not played it yet. It won't take another 5 years.