Players can't cast spells from graveyards or activate abilities of cards in graveyards.
Whenever a creature dies, you gain 1 life.
-1W is a fine mana cost for GY hate cards.
-For the same cost you get Rest in Piece or Containment priest.
-Creatures can still enter the battlefield from graveyards.
-Lifegain ist probably only situationally relevant.
-Triggered abilites still work.
-It allows for partially GY hate without shutting your own delve spells down.
Since it pretty much lets creatures untouched, i don't think this is playable.