Yeah IGN giving it a 5 usually means you could probably knock off a point of two given the state the game is in - I personally wouldn't give the game a rating at all. This is essentially the same broken mobile port of the game with updated models and lighting. And in a lot of cases worse since there are so many errors with their Ai upscaled stuff and bugs throughout the game. I'd say you could get a better experience with playing the originals but with mods instead - oh wait you can't since Rockstar has removed them from stores!
Just look at this mess :s
That is embarrassing for Rockstar and they should be ashamed for releasing the game in that state.