Check the forum post... Probably they will update the main website soon. I just installed the Mac version (sadly, it doesn't work well with my display)
Interestingly, when the game launches or exits on my mac, i can see my desktop flash briefly as it changes into and out of what looks like ultra-high-res mode, a kind of 1:1 pixel retina screen mode. I wonder if the game is rendering the oldschool resolution but then nearest-neighbor-scaling it to ultra high res for no good reason?
The new remastered version to be released in Summer is the same client as the normal version - I'm guessing 1.18 is actually here to test new engine for that release.