Thanks for the comment! Yeah, the tutorial is not great yet, sorry. So, basically:
Goal - get 3 special patients (click "Ritual" on the right). Each needs a specific organ type: human organs for the demon, insect for the groot, mechanical for the robot.
Where to get organs? From regular patients. Complete their requests (total stats of all your organs ≥ request value). Keep the best spare organs for rituals.
End day - button on the bottom left. Ready patients leave, new ones arrive with fresh organs.
That's the whole game for now :)