Here is my feedback:
Negatives:
-It wasn't obvious how to start a game on the book screen, I thought button coords for mouse just messed around on my display, its good I read comments below on how to start
-animation of cat looks a bit strange, but I don't sure I could do better myself, once I tried to make an animated sprites of cat for cat platfromer game, but walking animation was a mess
-too quick texts as for me, I'd like to see options to set speed of text, or let it go like in boss level, where you can skip it when you want
-strange innertia, either it too small, or too big, also its strange when you jump out of water, if you have run mode on you move very quickly in the air
-that was too much text, especially in gameplay moments, either you stay and wait for it, or just go and barely notice what they talk
-boss was cool, but I don't really like that survival type of battle, where you need to just wait for his death, If player knows the game, I think player should be rewarded with a possibility to finish him off quicker, at least doing something, not just waiting
Neutrals:
•I think you should freeze your game when it loses focus, or disable input, when I was typing notes on your game, it reacted to all that inputs
•speed of cat is a bit slow, but I appreciate autorun option
•I think you should let players collect coins from the start and give them reward for this, if they collected them all, and coins sound seemed strange, but I think this part of game is something unfinished
•cat girl form looks unfinished and useless right away, also her art is less appealing for now, but I understand that it's w.i.p.
Positives:
+its interesting idea with two combined/separated characters
+really plesant sound effects and music
+adorable cute art
+I like how your sounds and music change under the water and other little details like that
+it was cool physics with liquid in boss battle, I really liked that
+overall it was interesting and fun game to play, thank you for that