I have lost track of the number of times I've bought Metal Slug 3, which usually isn't a good sign -- but it's one of those timeless games and I can't help myself. Absolutely no regrets. Temptation will arise once again in February when the game becomes available on Steam.
Besides the character-select screen's head-scratching artwork, this looks to be about what you would expect after so many ports. Of special note: DotEmu appears to be handling development alongside SNK, and there's online cooperative play plus cloud saving.
No word on a price yet, but the Steam landing page is active. I'm ready to zombie vomit.