It feels well constructed, the game continually finds small new ways to keep you invested wether it be with powerups, narrative, music, achievements, or aesthetic changes. Its simple and minimal but enough to keep me playing.
Presumably missing sound effects, walking and jumping notably
Killing the purple duck feels a bit bad, he makes such a cute noise when he dies
Maybe the player hitbox could be made smaller, i felt i got damaged on projectiles i wasnt touching
I feel rescuing your family members could have a bit more kick to it, at first i didnt realize thats what i was doing when i got them out of their prison. Maybe play a little melody or show some text/emoticons that shows their appreciation
The control on the mount feels maybe a bit too floaty... even the simple platforming to get the double jump took me a couple of tries but maybe that was intended
The boss battle was a fun increase in difficulty, but maybe too difficult. i was engaged for a while until i got the feeling i just couldnt beat him, i found a way to cheese trough him though (standing at the edge of the room makes it so the projectiles cant hit you) and got to the end. I noticed theres no cooldown on how often you can take damage, maybe adding post hit invulnerabilty could be enough to make the boss easier, or letting the player shoot the top projectiles. The boss was the most gameplay engaging part of the game and i enjoyed trying to beat him.
The AGDG statue at the end is cool, did not expect my sprite to appear. cheered me up. Curious to see what you do with the game next.