Six ways to fight
Warden holds the line and Templar keeps it standing. Pyromancer and Druid work at range, one burning ground, one mending it. Ranger cripples what chases you and never lets it close; Revenant takes its health back out of whatever it is hitting. Five or six skills each, unlocked by level, and your gear changes how you look.
Beasts, undead, elementals, constructs
Each family is drawn differently and takes damage differently. Fire burns beasts. Nature breaks constructs. Bosses hold the middle of every zone.
Mounts
A pony at level ten so the walking stops hurting. Everything faster than that is torn off a boss or handed over at the end of a quest chain.
Critters that fight beside you
Eleven species. A companion follows you, attacks what you attack, takes hits meant for you, and earns a share of the experience. Breed them for colours nobody else has, or take one off a boss with the bloodline to prove it.
Loot worth arguing over
Five rarities, random affixes, upgrade levels to +7 at the blacksmith, and durability that punishes you for ignoring him.
Work posted every few hours
A board by the west gate pays for thinning something out, clearing a road, or bringing down something with a name. Three jobs at a time, pitched at whatever level you are, in places you have not been.
Guilds with something to hold
Charter one, pool gold into a treasury, and build a vault out of it that anybody in the guild can leave gear in for whoever needs it next. Declare war on another and every kill between you counts towards a score that settles after a week.
Names you are given
Level 120 is not the end of it. Experience keeps counting as renown, and titles are earned for things you have actually done -- a thousand kills, every named beast in the world, the bottom of the Long Dark. You choose which one people see.
Thirty zones, one map
Forest, coast, crag, ash, frost, mire and waste, plus eleven torch-lit dungeons where you only see what your torch reaches.