The game still feels empty in survival aspect. After settling down and making a sustainable crop field there's no challenge in surviving. The only left thing to do then is constructing buildings which is technically creative mode with limitations. Here are some challenges to add to the survival aspect.
Animal
-all animals notice you from farther distance
-passive animals are rarer
-aggressive animals have better path finding AI that can follow you behind walls. Also they try to break through doors or windows if they find no other way in. For that, doors and windows should have hit points.
-all animals have higher hit points
Temperature
-different biomes and weathers have different temperature and you need different clothes to adjust to the environment.
-wetness. Rain and staying in water increases the wetness of the clothing of the character, which translates into body temperature. different clothes have different water proof value and umbrella significantly reduces the rate of getting wet.
Staying near fire decreases the wetness value.
Nutrition
-Different foods have different nutritional value which combine to set the character's nutrition which translates to different impacts like faster or slower reduction of hunger value and different rate of health regeneration. Cooked foods are more nutritional than raw foods. There are various cooking recipes and the more complex the recipes the more nutritional.
Sleep needs
Crafting consumes time
Encumbrance(encourages transport)
If the players don't like these they could always play creative mode.