Background image is distracting, otherwise, very good ! It could be gamified with points and fish reproducing, like try to find a way so that users have to maximize some kind of goal while making tradeoffs. Like city building games
Game probably needs some way of making the player feel more invested in the game. Maybe you can only place so many particles per day, and then you have to wait until the next day. Or you can pay to get more particles now. If you could pay for some bonus materials that would be great too. Though I'd rather unlock them randomly from a kind of loot box system. And how come I can't level up? I don't feel like I'm making…
Not everything needs to be a fully developed game. Sometimes people make things for gasp the fun of it and not to build a comprehensive game that will appeal to everyone and their demanding cousins.