Something that looks like “real” swinging is much harder to code. Because the “rope” is approximated as a sequence of linked springs, I found it too difficult to get natural swinging motion AND have something anywhere near stable.
I could play around with the numbers and improve things I’m sure, but it takes more time than I can spare to get it “right”. Heck I don’t even have a decent screen shot or web page 
If the rope springs can only compress, but not expand, you might get closer to rope physics. (If that’s the goal)
It’s putting in any sort of “hard” constraint that creates the problem. It then becomes a massive inverse kinematics problem, which I would love to know how to do, but I don’t 
(And I’ve looked for the info with Google… but didn’t find anything that spoke to my level. It’s been over ten years since I was doing any sort of advanced math in university.)
It’s funny how all the time, money and effort spent at university never really gets used until a Java 4K compo 
I recognize it all too well… 
Great game, but I also think that the speed could be a bit faster/increase faster. There is a danger you get bored before it gets challenging… I think insane-o-spring bungie grappel is what it should be rather than rope, even though it might be a bit on the over insano side, but that’s better than too little insan-o