I don't really get the game's goal. I inject red poison for red patient, but when I don't have anymore red injection, what do I do? I inject him with another color, but what does this do?
You can jump and collect syringes which appear from time to time. This gives you additional substance to a random syringe. If you don't have the needed cure, you need to sacrifice the patients. The goal of this game is not to cure everyone, but to keep a balance in the world's population. Watch the right corner in the game to read the current state of that. I hope it helps. If you have more questions, feel free to ask 😉