Super solid for a first game, good job!
I like the fact that the level doesn't end after the timer is up, so you can still get the order done, you're just dealing with the stress factor
But I do think that the stress system needs a little bit of tweaking - donating removes a chunk, but since you can't bank stress relief, you want to donate around halfway through, but by the time you start another cookie, you're already back to where your stress meter was, since it increases faster with lower time. You could help with this by pausing stress build up for a short time after donating a cookie, that way you can balance needing to lose a cookie towards the order with more easily being able to make better quality cookies for a slightly longer time.
I think the minigames are simple and easy to get the hang of once you mess around with it in the first level, but each station having its own minigame would go a long way in helping gameplay variety.
But otherwise its a nice idea, and you did a great job with the art and incorporating unique mechanics. Great work!