-Your objective is to travel to the west coast of America, while delivering packages and making allies for Bridges
-You must safely travel across rough terrain while managing things like keeping your BB safe so you can maneuver around BTs safely, your health (which is measured in ml, so you can bleed out possibly?), and the durability of your packages and boots
-You can use various tools such as ladders and climbing rope (and more i've seen in menus, but can't identify) to maneuver around the terrain, and you have a limited amount of them, so if you get distracted by BTs or human enemies, you might have to leave something behind, which will hinder your travelling capabilities. There are going to be various exoskeletons that you can use, probably with different benefits and different cargo capacities. We only know of the "speed" exoskeleton, which judging by game logic is probably going to move faster than normal speeds but can only hold less items. The Ludens armor might be an end-game or secret exoskeleton/equipment
-Extremely varied locations like easy to traverse plains with small hills, rocky plateaus with claustrophobic crevices that you have to traverse past, and probably in, ruined cities, areas with lots of small mossy mountains and rivers, mars-like wastelands, massive mountains peaked with snow, snowy mountains, dense forests/swamp forests, and most likely more. According to leaks and speculation, possibly even the moon will be an end-game area. I wouldn't be surprised if there's even caves
-Various types of BTs, like the floating umbilical cord ones, based on cutscenes some that appear to be quadrupeds, when BTs catch you they can bring you to various miniboss-esque enemies that are dangerous
-When you die, you get transported to an ocean-like realm where you search for your body and items in first person, to come back to life
-When BTs eat a corpse, a voidout happens and leaves behind a crater. Possibly an aspect of gameplay as it is shown you can also deliver corpses and there was a cutscene showing a corpse being cremated, so you might also have to bag up and cremate any corpse you find to prevent craters that could interfere with travel.
-There is also Hades, the WW1 realm, which others also say you go when you die. Though with the confirmed ocean realm, that doesn't make much sense. If you fail to find your body and come back to life in time in the ocean realm, then perhaps a voidout happens at your corpse, you lose all the packages you were delivering, and you get sent to Hades where you have to fight/find a way out to restore your disintegrated body and come back to life
-A part of one of the trailers shows you breaking open a case for your rifle, and in the menu when pulling out a ladder in release trailer, there was a rifle, so it is possible that the rifle is something you have to opt in to bring along if you think your path is going to be especially dangerous, and it will add onto your weight so you don't always want to bring it, but your handgun will always be with you
-There are multiple delivery companies, the hazmat looking people probably one of them because they were trying to steal packages. Will most likely also have to watch out for rival delivery companies trying to hijack your packages, and they will probably also have varying equipment to attack you, but most will most likely not use guns because they don't want to damage the packages. You most likely will also be able to steal their packages and deliver them
-You might get to temporarily use superpower things like the golden mask later in the game