Untangle is a spatial puzzle game where you drag nodes around until no lines cross. It is based on Planarity and Simon Tatham's puzzle game of the same name.
How to play
Drag a node to move it around the board. Lines connected to that node move with it.
Rearrange the nodes until every line has a clear path. Crossing lines are highlighted so you can see what still needs fixing.
The board is solved when no lines overlap.
Tips
If you get stuck, try manipulating the nodes in a way you haven't done before.