I didn't run into any problems with the prismatic cores requirement. I was missing, I believe, three of them by the time I ran into the requirement at the end... And because of the way things stand out in the scenery, I had plenty of ideas as to where to find more.
It's pretty overtly a game about exploration, after all, so don't be afraid to go get lost in exploring what's there to be explored.
That said, the by-far-larger issues of the game lie in technical problems it has on console (loading times are a big one, and there's a few areas with inexplicable framerate issues - I suspect these are the majority of where the development time for the Definitive Edition went), and the fact that there are rather substantial inaccessible areas that are very obviously intended to be accessible by a Corebot frame that's not in the game (the T8-NK, which was even in promotional material, and has a spot in the menus left empty for it), and are basically empty outside of the terrain if you manage to get there without it.