The last (18th) level in Branches (chapter 5) seems to have a bug where one of the switch nodes will only 'go around' once and then get stuck in one position, making one of the connected nodes inaccessible. I managed to pass the level regardless by planning for a single 'go around' (so no rush!) but just wanted to let you know. I'm guessing it has something to do with how the switch will skip over 'finished' nodes, maybe it's mistakenly thinking an 'unfinished' node is finished? I don't have a mid-game screenshot, but i circled the node that breaks. I'm on Linux btw