Here are the differences I've noticed in my gameplay:
Played
1. Will not be culled
2. Will age up unless you've chosen 'No' for auto aging played Sims
3. Will have an urn on their home lot if they're housed when they die, or on another lot if they were not home at the time of death
Unplayed
1. Can be culled - unless put in the 'My Favorites' tab in Household Inventory and/or are housed
2. Will not age unless you've checked the auto aging box for them
3. Will not have an urn on their home lot if housed or anywhere else when they die unless your Sim is present to witness the death