You've managed to crash land on a dry, dusty planet. No water, no food, no real supplies. The first challenge, to survive the blazing heat where every drop of water is precious.
So many modpacks and maps try making gameplay harder by altering hunger. Very few, in fact none I know of, look at Minecraft's other normally abundant resource, water. Well, now here it is the limited resource. Try not to dehydrate.
Map is set to vanilla hardcore. This is deliberate. Sync is installed. You need more lives, you build more shells, you won't get hearts like in Agrarian Skies.