Really nice concept and execution with the swinging and dashing! I liked how the game focused and iterated on it, especially with the ballon power up, the swinging and dashing complemented each other greatly, I only felt that sometimes the swing control was slightly "stiff", not sure how to explain it, but maybe it came from having to grapple in tight spaces, altought eventually I got used to it.
And the combat was nice, especially with the "grapple and dash" Bee enemy, now, surprisingly the little blobs where the toughest enemy to fight haha, they sometimes damaged me while I was dashing (perhaps because I was too close? not sure), so perhaps they are harder than they should, not sure. I also found perhaps one small bug, one of the blob enemies became invincible in the room with the grappling hook extension, he never took damage, not sure why.
Also the final boss was visually cool, but he could be even cooler if perhaps he had like a second flying form or similar where you have to use the ballon and grapple mechanics more.
For the rest, if polished more with some ambiance music and more background variations and a Map, the game could be a truly complete and awesome experience.
But overall, even without music and visual variety, the game is pretty fun and unique to move and dash around with enemies, so congrats!