It's worth remembering that the business model always affects the game design. 6th gen consoles were arguably the most "pure", since obtuse games with strategy guide and hint hotline revenue streams were just about dead thanks to free GameFAQs, and DLC had yet to be introduced. Still, their incentives were to cheaply make as much "value" as they could, which meant churning out levels so that they could put a higher number on the back of the box for how much content you got for your $50 (a little over $80 in today's money). They also knew there was a good chance people would rent the game and decide to buy it off of that experience, so the best content was typically front-loaded, and then you'd get a lot of padded levels in the later parts of the game. It was rare that I would finish games back then, because often times a game would start strong and then end up filling big rooms, that look a whole lot like earlier big rooms, with trash mobs repeating the same simple loop over and over.