Hey there! I think you have a lot of potential here to expand upon! As the game stands currently, unfortunately I had a frustrating time, as much as I wanted to have fun with the grappling! Here are a few things that stood out for me:

• For me, the green stripey background competed with the player and terrain. When I was flying around with a lot of momentum, the effect produced by zooming past the stripes quickly was a bit ouchy to look at, so something more subtle might be a better choice. That said, I liked the player character and terrain tileset you chose!
• It feels like you achieved the type of movement you were going for with the grapple, but I think there needs to be some kind of UI system on the edges of the camera view or something that helps you to identify in which directions there are surfaces you can grapple to, and maybe how close they are. As it stands, movement felt a bit frustrating to me, because I had to sort of test in directions where I couldn't see walls, and then when they were really far away I'd zoom away super far and fast without meaning to. At one point this resulted in me being flung out of the play area at a sickening speed and into a void of blackness lol. I wanted to spend more time exploring, but even when I got more of a handle on the grapple, I found it really hard to figure out how to go in a specific direction or how to get up onto the top of ledges / platforms.
• I never found any of the mentioned energy I was supposed to be collecting - maybe I misinterpreted what that means, or just couldn't progress in the map as intended. 

I think this idea definitely has legs, and just needs some more development so the player has a bit better sense of control over their movement through the map. Great effort!

I think this accomplishes exactly what it set out to accomplish and I think you should be proud of that! The grapple felt quite nice so once you build a more complex and complete game around that as a main mechanic it could end up being super cool! Overall quite nice!

The grapple is really zippy and fun to use, it would make a good ability to earn in a Metroidvania, good work

Good mechanics, I see potential here, I didn’t see the Metroidvania concept, but I liked, good job.