Depends on what edition of DnD you're referring to. Pathfinder is closest to the 3.5 edition DnD, PF is very rules intensive, massive amounts of classes, races, feats, spells, etc. PF prides itself on its diversity of options, mechanical nuance and heavy character development.
Now if you were to compare PF to 5e DnD, then it's way more complex then 5e, which can be a good thing and can be very bad, especially for a new player. I can't speak for this video game, but there are so many options and features to the classes in PF that it can be intimidating to a new player. Every class has sub-classes called archetypes, different feats, skills, possibly racial traits, the ability to specialize your character in PF is almost endless.