Loving the game as it is so far!
If I could make some suggestions on things to add:
"Trainee Mode" - Nothing changes about the gameplay, except you get "critique" on what you got wrong with any order (maybe even an "Attaboy!" if you manage to get S rank on an order) so you can note it down and improved. (Maybe played as a grouchy kitchen veteran or something?) You still have to get the orders right and no do-overs without backing out to main menu and restarting the level.
Maybe a challenge mode where either you get a random one of the negative effects OR you get one specific negative effect of your choice over and over? I probably wouldn't use it, but someone might like the extra challenge!
This one's probably a huge stretch, but maybe a new game+ mode if you get an S rank? Either nothing changes except for your customers all starting at max size, or, here's the stretch part, maybe the customers are all swapped out for others- possibly cameos like Spacethumper's Pilot or the Reindeer from that one christmas game jam.
The only critique I have is it's not really clear how much of or IF there's an effect on how "neat" your stack of burger is. Like I understand that everything must be in the right order, but I couldn't tell if it mattered if I, say, made a diagonal burger instead of a straight up and down one until I started experimenting.
Now that I type this that might actually be intentional, lol.