I really like the aesthetics you've built over time. You've made nice touches with the animation, and the special effects are crisp and well intended with their color schemes. Your backgrounds are lush in the overworld, the character moves well, the ducking frame is a super nice touch, and you have a lot of good mechanics in mind.
Some personal suggestions for the game mechanics would be to increase the range of some of her attacks. Approaching enemies from the air is extremely difficult with such a stunted range and so much landing lag. Fighting enemies on the floor can be aggravating instead of challenging because of the range of the attack in addition to the delay. I did notice that the wind-up and recovery animations for the upgraded weapons are improved. The delay makes it so you have to be deliberate to hit enemies, but attacking as a whole doesn't feel very satisfying with her main weapon. There is very little practical use for charging up your main attack, since most enemies are fairly mobile and the window of opportunity to set it up will only get stuffed by an oncoming enemy.
The landing lag of an air attack lasts quite a while (maybe reducing it could allow Gale to be more mobile), and while being able to jump backwards with a retreating air attack is nice, being able to turn around in mid-air would be better, in my opinion (but disable turning around in mid air when Gale is in the air attack animation)
There also seems to be a lot of lag with rolling, probably to prevent people from spamming it, but it's nice that you can cancel the lag when you roll off an edge. I'm always tempted to roll and keep rolling, but it's good you're forcing that out of my system.
The sub weapons for the most part are all great.
Javelin feels super nice, bombs are timed well too, and dropping them down or throwing them feels satisfying. Your puzzles and mechanics for the sub weapons are clever and well utilized.
What would be nice for the slingshot is if you hold the fire button, you can hold the position of the aiming while moving forward and backwards, like how Yoshi's Island handles it.
I feel the stamina system is clever, although I wish it would recharge faster so I would have less moments of waiting in between, even though it's designed this way to be intentional with its usage of attacks.
When you receive an upgrade it'd be great if it auto-equips and can then be changed or equipped into previous weapons if I want to. This is a bit minor, but when I receive an upgrade as well, going through the text prompt is a bit redundant when I know what it should do the majority of the time.
Your sound mixing is phenomenal. Major props to the composer / sound designer as well. I like how you have the timers based off of Wind Waker, or one of the sound clips from "The Achievement Game". Most of the sounds are responsive, you have nice effects and filters to give them texture and grain when you need them too.
The presentation of the menu is awfully nice as well! Overall your visual aesthetics are very solid, animations feel fluid, crisp, and responsive, you have some action puzzle elements in this game that feel very rewarding, backtracking is a little tedious, but adding mysteries and rewards feel super nice. You have a good grasp of the design of the game. There is still a bit to improve on if you want to work at this, but this is coming along swimmingly. I'm impressed with what you've done.
Being able to make this game in full screen mode has been a boon to my experience playing this too! I love those little tidbits.
You don't ever have to take any of my advice. These are just things I personally would enjoy being implemented to make my experience as enjoyable as possible.
I hope this helps just a little. If you ever want to talk game design or animations, I'm a Character Animation major from CalArts. I want to make games of my own as well. Er, rather I am making a game of my own currently.
I wish you the very best. You've got quite the gem here online. I feel like this should eventually be a full fledged game for sale, it's definitely on its way with some polishing here and there. You are really damn good.