You have a working game, Congrats! That is not something just anyone can accomplish so kudos to you.
Unfortunately it isn't a very good game and strongly reemphasizes why pure RNG is actually really bad game design.
Gameplay: Tremendously Frustrating but difficulty isn't exactly the issue, because difficulty implies agency and skill which is unfortunately not a part of this conversation because RNG took them out behind the chemical shed and shot them both dead. The puzzles are actually easy but I frequently find the puzzles impossible to solve because I simply cannot get the pipes I need, instead I keep getting the same corner pipe that is completely useless over and over and over and over and over again. (At one point I had like ten of them in a far corner while I was trying to get something I could actually use and still had 4 of those same corner pieces in my available pipes.) Also cross pipes (and the thankfully absent T pipes) are no bueno because they increase the difficulty several fold because you triple your outputs.
If I were to redesign this in anyway, I would toss the Pipe box out the window and instead do something similar to Bioshock where all the pipes are already there, and the pipes necessary to solve the puzzle are guaranteed to be present but scrambled in with a bunch of other pipes, though I wouldn't hide them under covers or anything.
Aesthetics: Needs a lot of work. Especially the very flat and boxy art, very 20nots MS Paint. Also the game can be larger than that small corner it seems to insist upon, but that is a consistent problem, you have a ton of space with nothing but flat color to occupy it.
Story/Scenes: Not pretty but cute.
