I was thinking why not put aging into Minecraft as a mod and maybe even a plugin If that may Work. When you first start a new minecraft world You will have a number of days till you age. When you first start it you start out at age 10. Then after maybe 50 days gone by you age to 11 years old. How ever Minecraft time works. At a old age you get really slow and mine and do other activities slower then you do normally. Till you hit a certain old age you Die.
If you use this idea you must give me some sort of credit for the Idea.