Create a path of same color nodes of length K (Default K = 16) to win. Players take turns placing new nodes or reinforcing existing nodes. Click in empty to create a new node of your color attached to existing nodes. A new node will be attached to all nodes within the circular cursor. Each attached node will be shifted one degree to the color of the newly placed node. Neutral (gray) nodes will adopt the attached color while nodes of another color will be shifted towards neutral. Nodes can be reinforced to resist color shifting. A reinforced node is differentiable by its solid coloration. When a hostile color shift is applied to a reinforced node it becomes a standard nodes but retains its color. Friendly nodes can be clicked in order to "pulse" adjacent nodes. Clicking a friendly node reinforces that node and color shifts all adjacent nodes by one; all adjacent friendly nodes will be reinforced. Attaching new nodes to friendly nodes does not reinforce them. Finally, any neutral node adjacent to a friendly node can be clicked in order to be deleted. This is a ridiculous rule and really never should have been included.
Choosing the "Online" option will allow you to play with another player remotely. However, there are some limitations which are not effectively communicated. Once connected, each player has one minute to move every move before their connection times out and their game ends. Players are paired in the order in which they join. This seemed practical during development as the game had an expected maximum player base of 1. If you've found yourself here and you aren't me then you can give the online multiplayer a try by opening a new browser tab to the same page and playing against yourself. The svg window and board topology are preset and identical for all online players in order to prevent unsynchronized board positions. While this still happens, it occurs to a much smaller degree and minimally affects gameplay.
Local multiplayer allows for the game to be played on one machine. None of the problems inherent to distributed computing and networking exist here and therefore it is feasible to play with different board types and different simulation settings. That isn't to say that it is infeasible to do any of these things over a network, but I do not have the time or motivation at the time I write this in order to make that a reality. I would much rather invest the effort into modifying the rules so that this game is actually enjoyable and playable. Who would have thought that people aren't very good at finding longest paths in arbitrary graphs?