The grappling hook arrows are a really neat idea! Loved the slow down effect; though an aim line would have been cool, I found that I never needed it to hit my targets. The glowing is a nice touch.
For feedback, the game could have benefited from quality of life things like a health indicator and damage feedback on enemies. The core grappling mechanic could also be tweaked to be easier to manipulate your character.
Awesome job!