This demo is very, very interesting so far and I see a ton of potential in this. Obviously, this is just a demo featuring three shifts, but the possibilities for what this could be are expansive.
I feel like most criticisms I have with it are ultimately just a product of it being a demo, which is a good thing. (Those mostly just include a desire for more content or variety in certain places, which is of course common in demos)
Although healing your party seems maybe too difficult, at least for an early section of the game. I know that's the point, it's meant to be a challenging game where you're frequently being beaten down.
The idea of downsides with the healing items is cool. Cigarettes damage you once but slowly heal after that, expired energy bars are the reverse. There's lunches which can be used as healing but also there's other uses you want to hold onto them for. Then there's breaks.
But taking damage from battles, as well as just from random chance from performing certain tasks during the shift is inevitable, but difficult to plan around. The cigarettes and bars never felt too useful, as the regen of cigarettes ends at the end of a battle and takes away health so using them when someone is already very low feels too risky. These items can only be used during battles when you also need to manage whether or not you want to risk escaping, attacking the enemies to limit the damage you receive as quickly as possible, etc. so finding a good chance to use them is rare. Replacing dying party members with new employees is a possible solution, but like with healing at breaks it's unpredictable.
Then again, it's likely that it is entirely intended for there to be such a steep level of challenge and I shouldn't really be making this criticism. The oppressive atmosphere is apparent here, and that's one of this game's biggest strengths, the extremely limited healing can be frustrating but it contributes to it. I hope in the future a balance could be achieved between having a health system that can be better planned around and not watering down the challenge and atmosphere too much.
I wish you luck on this! I think everyone involved with this game is on track to create an extremely unique experience.