Giving up on this at the second bird boss - it's just not fun, and having to climb all the way back down and then back up the mountain to get any upgrades means I can't really do much to make it more manageable.
The bosses were a low point here. They start out decent and then get consistently worse over time. The first one is simple and works fine for an introductory boss, the second one is flawed but I still had some fun with it, and then the two bosses I fought after that were both absurdly tanky and fully uninteresting to fight. Every boss attack in this game seems to be either completely trivial to dodge (most of the bird's attacks don't even focus on the player and can be dodged by just standing still for most of the phase), or they're the bird's laser attack. God I hate that attack. The flames appear with no telegraph before the attack proper even begins, so you just. Instantly take damage if you happened to end the last phase standing in the wrong spot, and then the two flame patterns are treated as equal and have a 50/50 chance of appearing despite being radically different in how they actually effect the attack - the horizontal flames make it relatively easy and even decently fun to dodge the lasers by moving back and forth and then dashing across the lasers when you need to turn around, but for the vertical ones I genuinely cannot imagine any way to consistently avoid the lasers there. The lasers are now much more closely aligned with the space you have to move in, so you can't avoid them by just moving back and forth through the lanes like you can with the horizontal beams because they just take up so much more of the space; trying to move horizontally doesn't work because for some godforsaken reason the flames are placed exactly close enough together that trying to dash over one row will regularly faceplant you directly into the next; and when I tried to just repeatedly dash through the lasers I got killed by their lingering hitboxes stacking up over the space. Every time it used the vertical flame pattern I'd come out of the phase with at best a third of my healthbar gone, which meant the fight came down to tediously waiting for the extremely slow and mind numbingly trivial dash and thunder phases where the bird is just... fully invulnerable to damage despite these taking up the majority of the fight, standing next to it and wailing on it with the disc for the like ten seconds the fireball phase lasts, and then praying that it used the correct flame pattern in the laser attack often enough that I could survive. Repeat for cycle after cycle after cycle as I'm left wondering just how much health the stupid thing has, until I inevitably lose most of my health to vertical flame patterns and then accidentally dash of the platform and die. Most of these phases are identical to the first fight against the boss, where they already wore thin after a few cycles - by this point there is nothing even slightly engaging left to them at all, leaving them as soul sucking time filler while I wait for the make or break laser attack.
The third boss had similar issues with being invulnerable most of the time combined with a massive health pool. The fight is interesting at first - you have to work around the walls the boss makes to defeat the towers, the whirlwind attack is genuinely difficult and fun to figure out how to dodge... but within a few minutes the towers are gone, then it takes maybe a few more cycles for me to figure out how to dodge the whirlwind, then within a few more cycles its started getting tedious... and there's still dozens of cycles left to go. That one, at least, was easy enough that it didn't take multiple tries, so I ended up pushing through it, but I had I died close to the end (which I nearly did as I started slipping up from boredom) there's a good chance I would've just dropped the game there.
I'm not sure how much else to comment on. Maybe I should've just given up at the end of my previous session and written a review then, because with this session being just failed attempts at the second bird the bosses are all that's on my mind. I left some other feedback on discord during the rest of my playthrough so maybe that'll have to do.
As far as positives... the mvm references were fun, and the visuals are decent. Wish I'd gotten to see the end of my sidequest. I think the core "platforming" mechanic of dashing over gaps in a top-down setting is interesting and shows promise too, but it's still rather janky and often frustrating in its current state (though significantly better than it was in the beta version I played.)