It's a stretch to call any game in the GTA franchise "underrated" as the franchise has done extremely well both commercially and critically. The games have had varying degrees of success but they have been hugely successful nonetheless.
However, there are a few games in the series that receive more love than others. GTA IV is an example of one such game that, over the years, hasn't gotten the love that other games in the series, like GTA Vice City, do.
However, GTA IV is perhaps Rockstar Games' most risky and ambitious title as the developers looked to shake things up drastically. Here are a few reasons why GTA IV is one of the best games in the series but does not get enough credit.
Reasons why GTA IV is the most underrated title in the franchise
1) Believable Protagonist
The protagonist of GTA IV isn't an eccentric criminal with ambitions of taking over the city. Instead, he is a man simply looking to get by and get even. Niko Belic is a man tortured by his past and is now looking to create a better life for himself away from crime.
His tragic story arc sees him plunged back into a world of crime and creates one of the most believable protagonists in the series. Players could get behind Niko's story and feel a connection with him, more so than some of the other characters in the series (we're looking at you, Trevor).
2) The right amount of grit and humour
GTA IV is a much more grounded affair in the series and doesn't necessarily have the "holy crap" moments of the franchise such as stealing a jetpack from a secret government facility.
However, the game's biggest moments come emotionally and with quieter episodes of the brilliant neo-noir style story. Its influences from Russian crime dramas is apparent but that is not to say the game is completely devoid of humour.
Niko isn't just a cold and merciless killer but rather a complete multi-dimensional character who is as witty as he is lethal. The writing of the game remains as sharp as it has ever been and is filled with moments of levity.
3) World-building and Liberty City
It could be argued that the soulless colour palette and desaturated effect that the game creates only adds to the world-building and personality of Liberty City. As a vast metropolitan that severely lacks sympathy for the downtrodden, Liberty City is extremely well-realised.
While it isn't a light-hearted neon paradise such as Vice City, it has a lot of personality, that shines in its characters, colours and, most importantly, the radio chatter.
4) Realistic physics add to the game's authenticity
One of the most controversial aspects of GTA IV came in the way of its more realistic driving mechanic. Cars in the game have actual weight to them, and drifting around corners is not as easy as it was in previous games.
Cars move with purpose, and each little steering input has consequences. This only added to the authentic and grounded nature of the game. Rarely ever have gameplay mechanics been used in the GTA games so thematically as in this game.
5) Narrative Complexity
The story of GTA IV is definitely the best aspect of the game, and it is ambitious in every sense of the word. The game aimed to tell a more grounded and darker story than the other games in the franchise.
It appeared to deal with extremely real and heavy issues, with a lot of the subjects relevant even today. GTA's handling of topical issues and subjects have largely been done with the subtlety of a bull in a china shop, but not in GTA IV.
The game handles subjects such as PTSD, immigration and many others with a lot more nuance than other games in the series.