Whoa, I never realized Dr. Mario was a day and date cross-platform release from Nintendo for GB and FC! July 27, 1990. That's got to be one of the first cross-platform day and date Nintendo releases. Heck, I don't think there are many!
It's funny I hadn't thought of the good Doctor previously when we discussed the hair renders. I wonder which I encountered first, GB Dr. Mario or SM64. Probably the GB version. I think with the head mirror drawing the eye so much it doesn't show off Mario's tousled 'do to the same extent.
It's charming in the Galaxy games but I like the messy way it looks in 64 a lot, too.
Anyway, as to your question about the renders. I think they look amazingly high quality, especially in game, though without the charming trappings of a Nintendo world in the same way, I don't think they have the same feel to me somehow. I don't know how to put it into words exactly. M+R very much feels like a Rabbids game with Mario trappings to me, not as a dig against it, it's just less aesthetically of interest to me personally. So Mario and co. look good but there's not that Nintendo extra visual hook to have me associate this particular render in my mind, like the Bee Mushroom or Super Bell immediately bring to mind Mario's look from those specific games. I like the look of Tuttorio. I don't care much for the cover render, looks strange to me. /admitted Nintendo fanboy