I played the survival beta for about 12 hours. here is my recomendations. Offer the option to select a diffuculty level seperate from your need to eat, sleep, drink, and disease. Offer the option to fast travel, or not. Offer the option to be able to save or not. More options, less "all in one". Unless you offer "special content" playing it on the full hardcore mode. The mod community, has created the rest, backpack, tent, and pack-mule