Hey, I posted this review on discord for you already, but thought I'd post it here too for others to see.
The concept itself is pretty cute. Speaking personally, I'm in a long distance relationship (dating the artist I worked on my game with) so the title and concept honestly speak to me on a personal level.
However, my first impression of your game when I saw it was "I can't read that title in the promotional image because of the font and colors". I imagine it was a choice made because of the multi-colored slimes that combine together. But, the colors and font on the main menu and promotional image are very hard to read in my opinion. If i didn't see the title of the game on itch, I'd have no clue what the game was called. The credits page in-game is a little better, I can read everything. But the coloration make it feel a little...generic? for lack of a better word. considering this is in your promotional image for the game, I wanted to bring it up to you. for me, the first impression being "I can't read that text" isn't a good first impression to have, in my opinion.
regarding sound design, everything is relaxing. the sound does what it's supposed to do, it's fairly good across the board.
regarding gameplay, it felt like there wasn't much to do, I suppose? the whole game is collecting items to combine the slimes together. however, it's just moving around the map. nothing to make it stand out, at all. take mario for example. he has fun movement, has to avoid enemies, his jump is always fun to control, he's a joy to play as. but here it was simple wasd controls moving around. it wasn't horrible, mind you. the gameplay just felt a little bland to me. it felt like a "that's it?" type of thing when I did the first level. I understand the minor puzzle elements behind it, but sometimes I was unclear as to what certain items did or even what they were, beyond the boat.
my overall impression of the game is, it has a really cute concept and I want to love it. but it felt like it was missing something gameplay wise, like it was a little too simple, I guess? it's hard to put exactly what I want to say into words, but I think that's my overall thoughts on it. I want to like it, and it's okay, but it feels like it's missing something. but, you did make and submit a game. that's a major accomplishment and you should be proud, it isn't easy.