If you put it that way, yes indeed. (I realised since posting that I could have come across as saying “gameplay is ALWAYS dependent completely on the quality of the graphics”, which isn’t what I intended…)
I’ve been around long enough to have seen the “ohmygod, all the games in the last 6 months have been graphics, graphics, graphics, and yet the gameplay sucks - what’s happened? why have the studios/publishers become obsessed with graphics when its the gameplay that really matters?” concept happen about four or five times (originally sparked off every few years by the mainstream games magazines, now recurring much more often online in games news-sites). I’d call it a “debate”, except that the arguments have been so one-sided and so strong that there’s never really been much of a counter-argument worth listening to :).
…and until about 4 years ago, I agreed. It’s simple thought-experiment stuff: “Well, it’s obvious, init? Gameplay trumps graphics. Would I have played [xenon2] wihtout the grapihcs? Course I would!”. In fact, experience shows that although this is believable, it isn’t true. If you remove Xenon2’s graphics (get a good clone and destroy/corrupt the graphics), people don’t seem to find it fun - and this is mainly people who have very fond memories of the original. The easier one is to unplug the soundcard! (X2 of course being one of the few games of that era where the soundtrack was really important).
Or another example: when I was in my prime as an FPS player, I played Quake, Q3 and UT. But not Q2 (and judging by responses of people I played, you were either a Q1 person or a Q2 person; it polarised much of the community). My only reason for not playing Q2 was that I found the graphics so extremely dissatisfying. Quake had a “chunky charm” - a style of its own, as distinctive as Art Deco, or the paintings of Klimt or Muchas. And gibs had a solid “feel” to them, the way they were animated and the bulkiness of the bits. Q2 felt completely different - all the characters seemed anorexic compared to Q1, and it felt like killing people made out of cardboard, because there was so little substance to them and their world. Q3 brought back a more “funky” style (many people simplistically described it as “cartoony” but that’s woefully inaccurate). It was bright and colourful, compared to Q1’s drab “any colour you want, as long as it’s brown”, but the colours really helped the game - you could tell someone’s weapon milliseconds before your brain had recognized the shape they were holding simply by the dominant colour at chest height (red for rocket launcher, etc).
Just don’t ask me why and how graphics are important to gameplay. The colour-coding in Q3 is obviously one of the ways they affect gameplay, but I couldn’t tell you why Q1’s chunkiness is so appealling and adds so much - it just is (perhaps it’s simply the same kind of appeal of any piece of art? Shrug). Similarly, Warcraft without the (for want of a better word) cartoony graphics loses tons of it’s appeal. And (for me) it’s definitely not any particular love of those graphics (W1 and W2 were pretty uninspiring, to say the least!)…I don’t know why it works! 
P.S. IMHO, the fluffies in AF are the only bits to have really good (and here I mean “in that they seem to affect the gameplay”) graphics…everything else seems generic (I’m not being rude, but I’ve played too many scrolling shoot-em-ups :)) in AF, but those fluffies - which actually look so fluffy I half expect to see stray hairs falling off them - are unique. And they (and their squashed little faces inside the bubbles :)) stick with me as the images I associate with AF. Everything else fades from memory between games.
Perhaps an interesting experiment (if PG had too much spare time :)) would be to re-do the rest of the graphics themed around the fluffy/bubble-fluffy graphics. At the moment I (personally) get a feeling of a mismatch between styles. The old-stylee 8bit “spaceships and aliens” (which for the most part would still work OK as graphics even if you had to massively down-sample them) set against new-style graphics that are only possible now we have infinite pallettes and very high resolutions - and which have been done in an artistic style of their own. I used to be an art student, hence my waxing lyrical about styles and artists, but perhaps that’s the point - perhaps the way that graphics affect gameplay is via their artistic style (e.g. bitmap-brothers games ALWAYS had the same distinctive style; you knew you were looking at a BB game just from any one screen shot).
Shrug. I’m sure there are people in the industry who actually understand this graphics/gameplay interplay, but I’ve never read or heard anything from them :(.
