Here's what the game looks like when I launch it.
Here's what it looks like after I click the fullscreen button.
Here is an example of a pair of nodes that I can't leave because only the other node is adjacent and onscreen. This is after I botched a node, but I've run into other scenarios where I can't progress when I haven't failed any.
I'm not sure how I got into this pair of nodes. It might have involved screen scroll, like, I exploited the slow scroll to click on the node before it left the screen.