Yes, fine tune the fundamentals of "is this thing fun to control". Content is a separate thing which I personally think is where a lot of modern games have gone wrong.

Nintendo are known for developing prototypes to figure out what is fun. Unlike modern "implement the design doc" process. There's a YouTube interview with someone from retro studios who explains this, Nintendo weren't interested in their design docs for metroid. I am hopeful remembering this correctly.

I haven't read this Goddard interview yet, but he was responsible for one of the best games of all time, 1080 snowboarding! What is completely bananas is that him and his mate ended up working at Nintendo and showing them how to do 3d graphics when they were teenagers.

I don't think it’s a conflict at all.

The invested time consistently into the things that were important to improve. If the art was good as-is (and it was), they didn’t waste time “perfecting” it further.

But as long as the gameplay itself still felt fuzzy or like there was friction, they spent time improving it up until their deadline. This was not a lack of project management, this was project management actually done well, for once.

In fact they accidentally optimized Super Mario 64 around its debug-mode performance, and shipped the game in that state, with debug symbols and everything. But they could get away with that because the game they shipped still landed in the performance budget they needed for the gameplay they were after.

Fine tuning is a huge deal. I made some simple games and spent a lot of time on fine tuning little details about the movement trying to nail the right "feeling". The feeling of Mario's movement in Mario 64 is excellent. That feeling immediately makes the game fun even when just jumping around aimlessly.

It's very difficult to get right. Even with the exact same programming logic, tiny tweaks to certain numbers around velocity, acceleration, friction, impulse, etc all can have a huge impact on feel. So even without changing anything besides a single static value here or there you can make the game feel very different. (and then of course you can also add more logic and tweak things endlessly, like adding coyote time, jumping higher when you hold the button, nudging the player slightly into place instead of stopping flat if they are grazing an object... and then other things like sounds and animations can themselves completely change the feel without changing the systems at all)

Feel is also something that is very subjective. Some people might like something that feels very tight and responsive, some people might like something that feels more floaty or forgiving. I tweaked one simple game I made to be a bit quicker and tighter, which caused more casual players to feel it was too hard and quickly stop playing, but more competitive players got highly engaged and played over and over to climb the leaderboard.