If you purchased the Mafia Trilogy Definitive Edition, then this was by far the gem of that purchase.
The story has been tweaked slightly to give the appearance that Tommy was more of a willing participant in joining the Mafia.
Missions have been streamlined. Characters are given more backstories so you bond to the characters. More light-hearted, fun, moments. You get more time with Tommy's eventual wife.
They new voice actor for Tommy gives him that much more character.
Overall it's everything you want from a remastered game (unlike its Mafia II counterpart). Tweaks where they are needed, huge graphic update, but the core remains unchanged.
You can play the 2002 Classic mode, which is just like the original. Speed limit is enforced. Health kits heal less. Enemies are better shots.
Or you can dive into the game in a more traditional Easy/Medium/Hard setting.
It borrows its gunplay and cover mechanics from Mafia 3. By no means is it perfect but it is improved immensely from original.
The achievements are pretty straight forward. A few collect achievements. Mostly story based. The hardest of the achievements is by far beat the game on Classic mode. Everything else is obtainable in 20 hours or less.
Relatively low hours required to complete.