Enter the combat the way you like, stealth or mindless, it depends only on you (at your own risk).
Chose how to play accordingly to your favorite gameplay. Stealth with a good analysis of the terrain ? You got everything for that, including binoculars, reconnaissance drone, and silenced takedowns.
You prefer to get directly into the fight ? Take your weapon, prepare some heal and go for it !
One mission, one environment. From the cold mountains to the hot desert, discover and enjoy the various landscape.
Each environment is different, and you must adapt to it. Be careful with hallucinations in the desert, make sure to stay warm in the mountains, keep oxygen to survive in radiated zone...
Each region offer you new gameplay besides the change of environment, from crossing the desert to swimming into the water of a mediterrannean archipelago, exploring caves in the mountains or ruins in a radioactive area.
Mod your weapons with the attachments you like.
Mod your weapons accordingly to your style of gameplay. Add a silencer to stay stealth, or take a compensator to face directly your enemies with less recoil.
Change your scope from long range to snipe enemies to red dot or holographic sight for close combat.
Add a flashlight to see in the darkness of the night...
Make a smart use of your gadgets and use your brain.
You have to use your map and compass to locate you in the world. Use your binoculars and your drone to spot the enemies and analyze the field.
Be careful with the security cameras, get around your enemies and be smarter than them to ensure the success of the mission.