I wish the rest of the game was as interesting as the second level in the forerunner substructures. And I DO wish, however that the level design encouraged exploration and had more side passages and level design/platforming like Quake, Doom Eternal and Metroid prime to give more purpose and mystery to the journey.
And instead of power cores, maybe The level design should require forerunner access codes to sections or other variety that would make it more interesting such as elevators to various subsections both above and below the main section, a more " ant colony" feel to the overarcing level design ( Like Metroid ) and require players to acquire a local cartographer and use that to explore with more platforming and large scale verticality, such as players having to grapple up hundreds of meters of layered columns, pillars and damaged floating sections to reach the surface from deep inside.
Otherwise, the architecture, lighting and forerunner detail was great, it just needs morelevel design that requires problem solving rather that just straight runs from point A to point B