The extra dimension of space makes a huge difference to the more usual two-dimensional mapping and travelling that people generally engage in. Even a multi-level dungeon with two-dimensional levels connected by stairs and ramps is nothing compared to the full freedom of three-dimensional navigation.
Mapping three dimensions for a game is non-trivial. You can record star system coordinates as Cartesian triplets and calculate distances using Pythagoras’s theorem, which will do the job, but visualising the “map” is tricky without complex graphing tools.
Various people have used tesseracts as dungeons, notably the original Baba Yaga’s Hut adventure published in Dragon magazine #83, but these are generally just two-dimensional maps with macro-geometry folded in four dimensions. But imagine setting a game in a four-dimensional (or higher!) space, where the heroes can actually travel not only east, west, north, south, up, down, but also some other set of mutually perpendicular directions.