There are more vaccinated people than not, and people with prior health conditions are more likely to be vaccinated so it's not surprising they would be represented in the ITU population.
A degree of rib fracture is the assumed outcome from successful CPR. The intended purpose of CPR is to physically compress the heart, which is typically well protected in the rib cage.
It's unfair to say that they haven't been succeeding until now. Plenty of trials with mRNA vaccines have been finding positive results in humans. However, the appetite for new vaccines is generally pretty low, aside from pandemic situations.
It's the same group, and probably very similar devices. the fusor.net website is a community for building these things and has loads of plans and tips.
Depends on how much actual cognition is involved, after playing many games it could easily just become repetition. Also could come at the expense of some of the others, like networking.