Quentin Having Personality, he barely shows any kind of personality in FG.
The stress meter, could be re implemented if you think it out right.
Being able to buy things from the gas station
MiTH watching you from a distance
Vandals being naughty
Most old models and art style felt good to me.
Most very unfinished items could have done sort of re implementation, there was a slingshot in HGs files that could be re used, I suppose.
The Alphas having a kind of decrepit and abandoned looking feel, the town feels too clean for what raven brooks is meant to be.
There are many other things but I'll call it enough on what I've listed