They have their place to describe certain things, but I find myself increasingly using different terminology when thinking about game design -
unpolished ► unfinished
Finishing and polishing are extremely different activities. As every gamedev knows, polishing something is usually the opposite of finishing it. Many of the best games have unpolished features which work just fine and in no way make the experience worse. I find that talking about a feature as unfinished (or unbalanced, or badly implemented) does a better job of communicating the actual problem and what's needed.
During playtesting, every game inevitably gets feedback telling them to scope creep, add detail, sand the corners, etc. Requests for polish are usually not helpful. What are useful are requests to finish unfinished things, fix mistakes, or adjust things which are not working as intended. It will make it easier for us to communciate and give feedback if we separate these two things in language, and stop using 'polish' as a catch all for 'work'.
juice ► gamefeel
Juice is so narrow I feel like it misses the point... We've clearly moved past the screenshake era of indie games, and many of us have discovered how limiting juice-oriented game design can be. Retro games often have very little juice, but still serve up strong gamefeel which devs today are still trying to reproduce.
Just like polish, juice is usually either (A) a thing you try to slap on at the end to make the game seem adequately loved, or (B) a thing you get unnecessarily mired in at the expense of real progress.
Gamefeel isn't something you add, it's something you hone or nurture. Gamefeel comes out of the way core things are implemented just as much as it comes from the vfx and animation. It's the product of a vision for how each piece should handle and interact -- choices which are always informed by the technical, tooling, and labor constraints of the game.
flavor
Every game has gamefeel in a certain sense, but they have different flavors, and some are much tastier. Tbh I think flavor is probably the most useful way to talk about it. Some flavors are familiar and grounding, like a home cooked meal. Some flavors are factory-made, market tested and mass produced to appeal to a broad demographic. Other flavors are acquired tastes, imparting a strong impression which repels unfamiliar palettes.
Personally, I want to make the game which is, like... some really weird spicy fermented stuff you've never had before, which you dont rly love at first, but your friend keeps saying it's the best shit, so you try it and think it's OK, but then the next day you are just craving that flavor, and you start eating it all the time until it eventually becomes a comfort food and you learn how to make your own ferment at home because you need that salty musty taste which made you scrunch your nose the first time you smelled it.