Thanks for playing! I have explained this in the discord but for completions sake if will post it here too:
We intended that you can use two grappling hooks to for example have less downtime as if you were using just one hook. For example if you would only have one hook: You would swing, release and then fly for a bit. Then you would have to use that hook to counteract the downward momentum again which is a bit slow. The trick in TwinHook is using both hooks almost simultaneously so that WHILE you are pulled towards the first grappling hook, you already shoot out the second one so that it can build up force (because the pulling force is like a quadratic function) and when you then release the first hook you instantly get pulled towards the second one with no downtime. I tried using that to its full extend on the GrappleWalking Level. If you look at the "Playthrough" in the Pause Menu, i was able to beat this level very quickly. However using both hooks efficiently takes some practice time.