A couple of things came to my mind when I played the game. I like the artstyle and presentation you had going on in your title card. The art itself during the level was nice but a few things bothered me there. I read later that its supposed to be lava (which I am questioning in a lab environment like that) but it really looks out of place and does not blend well with the rest of your games style. Also the water droplet sometimes doesnt stand out that much, I think it would have been great if it had more visual clarity or an outline or a shader effect that helps the player identify its position. Against the test tubes in I think level 4 it entirely blends in and is barely noticable.
Overall I think the player controller should have been a bit more fluid (get it, fluid as the player is a droplet) that would have been the icing on the cake. Also, a lot of foreground decorations are hindering the sight of the player, making levels such as level 2 or others way harder than they should be.
The level design was also very mixed. Some levels were great, others were more of a miss. You have a very hard to control player controller and I dont think precision platforming was the right choice, it was really frustarting from time to time. I still managed to beat it but I didnt like all the levels. Especially the ones where you had to dodge the falling droplets, those were quite frustrating.
The music fitted very well, I just wished there was a volume slider and it would not restart the loop on death. That way you hear much more of the song and it does not break your immersion. Also, perhaps a few more soundeffects for juice could be great.
Thats a lot of ifs and whens but I hope this feedback can help you with your game and game making journey. Solid entry!
Edit: I just saw that its your first game. Congrats on the release of it! Hope this feedback does not deter you from gamedev, I just hope it can help you :>