I think it's cute. Though, I felt a very real lack of feedback in the game. I didn't know when the game started whether the store was open or not, then when I opened and I took a ticket, I didn't know which piece corresponded to which description, then I didn't know what to do with the pieces until after I read your description below the game, and it took me until just now typing this on the submission page to look at the screenshot to see I should be able to put the label on the box. I made a robot that I wasn't sure if it was right or not, it got all boxed up, then I left the workbench, and when I went back into the workbench interface the box was missing, so I had to guess whether it was intended design or if the box was just gone. If I got into the flow of it and learned what everything meant, I would probably have a better time with the game, as it's kind of in the style of the Papa's Pizzeria games as far as I can tell, and I like the idea of putting the toys together (It also seems to me this could be your interpretation of the "unfinished projects" part of the theme and I like your creative take), but it really just wasn't clicking for me at first.
After going back in and trying it again, it was fun once I knew everything, and like I've read in the other comments you already know about the parts going missing after finishing a robot or two, but the idea is there. Props to you for making things work enough to convey your idea - I imagine it's tough to code it to recognize when the robot arm is attached to the body, or when the body part is in the bin, etc.