Disabilities (mental and physical)
I would love to have scoliosis and other disabilities to happen after a long fall or other causes of things like this. This includes breaking bones and needing wheelchairs. Also, after a terrible event like family dying, maybe they have a chance of getting PTSD, depression, anxiety etc. Furthermore, it would be nice if every now and then a child is born with ADHD, Autism, ect.
Maybe there could be cheats to add or get rid of them.
Hope you like these