This is a very specific bet to lose. haha
Overall the whole piece works as intended and gets a good chuckle with the various character's reactions, and luckily for the Captain, most of them are more interested in their own conversations and food. :P
I like variety of characters and how you didn't just stick with one mood or type of reaction, the combo of shiny surfaces mixed in with a dimly lit atmosphere. Interesting mix for a maid café. lol
They aren't really that many 'mistakes', so I'mma just list 'em off point form.
Mostly just stuff to watch out for next time, but I can respect the time crunch you told me about for this piece. :)
-Chutney's phone, since it's glowing and giving off enough light for pink to show up on his face, there'd be enough light to shine on his left shoulder (our right). The back of the phone obstructs the light so his right shoulder would be dark like it already is.
-Chutney isn't too far away from the Captain, so his lineart could be a little bit more crisp to match up with how you drew Captain with a bit more clarity since he's the focal point of the piece.
-If there is pink light illuminating parts of the drinks and the captain, there'd be a little bit of pink highlight on the couple o' crickets too.
-A bit more of a wall plug where the wire goes into the seats.
-If Ruby's hair is giving off enough of a glow for highlights to appear on Henry, then Ruby's backrest would have a bit of a pink glow as well.
Other than that, it's a fine piece.
Characters near the front of the pic have more detail and characters in the background are a little bit out of focus and more impressionist coloring. It all works out.
Keep it up!