Oh man that was a chaotic experience to start, but overall it was fun! I used to play tons of diner-dash style games and this gave me a nostalgia sweep. I really liked the music and design of the game overall! I thought the mechanics were fun, and I played for quite a while before noticing...
As for feedback: Like some other have pointed out, switching between keyboard and mouse inputs felt a bit un-intuitive at times. I think hard committing to one or the other would have been better for sure.
Given more time, I think the game would've really benefited from a tutorial. This would totally help with some of the confusion people had with the controls as well. With this type of gameplay, it's super easy to be overwhelmed initially. I'd say even something like a ramp-up period (longer timers, fewer customers) to start would make the experience more friendly as you start!