I love this The Incredible Machine style juice factory concept!
It wasn't clear to me whether the game expects players to place everything and then run the simulation (as in The Incredible Machine), or whether players are expected to add and remove elements while the simulation is running.
If it's the latter, not being able to move items around after placing them feels very cumbersome. Removing and re-adding is an option, but the simulation moves so quickly that that doesn't feel like a viable option.
I was able to finish all of the puzzles in the first level, but the truck didn't appear in the second level and I wasn't able to play further. Not being able to reset the current puzzle/not having the oranges count reset for each puzzle meant I ended up spending a lot of time on puzzles I'd already solved.
I was looking forward to seeing what the optional prompt "orange" might inspire in participants, and physics based juice puzzles is a fun expression of that!
I was concerned by the lack of credits. Is the background image in on the title screen public domain and/or available under an open culture licence?