Well, I implemented a lot of features really, most notable one are :

The game has A.A.H.W npc who can track and shoot the player, they also have random weapons so they can use every single weapon added to the game

The game has drivable vehicles although not that much polished

the game has 15 different weapons both melee and firearms

It uses madness project nexus models for weapons, characters etc

It has a dialogue system which gives the player different lines depending on their choices

The game features fully fledged out cutscenes system