I've recently been playing SNK Vs. Capcom: The Mark of the Millenium and one thing I think is pretty cool is how they handled the two-button control scheme - specifically with a tap/hold light/heavy sort of style - as well as a few other moves being attached to directional inputs (like for instance Guile's Reverse Spin Kick being a down-forward kick input, or Morrigan's Shell Kick being a downward kick input only when airborne.)
I think it's a really neat simplification of the traditional four/six button control schemes you'd see with games like that and I'm honestly a little surprised that it's not caught on in other more modern fighting games. That said, I'm not sure how I feel about blocking being a backward input to meet an attack. I'm not sure if I'd necessarily prefer a "block button", though. It feels sort of natural but odd - albeit, that might be just from my own lack of mechanical exposure to a lot of tradfighters. Also, the Styles are a pretty cool inclusion, but I'll admit I gravitated toward Average (the Street Fighter type) mostly because it was just a little easier for me to understand.
I also really like the artstyle, but that's generally the main thing people talk about in relation to that game anyway. It'd be fun to see a more modern game with a similar control scheme, though - I'm interested in how it'd feel with a less cartoony "look" overall, or if a part of the appeal boils down to the fact that it's a fairly simplified control scheme with a somewhat cartoonish artstyle overall.
Seems like a fun experience! I think it got rereleased fairly recently at some point, though I don't remember for sure when and where. That said, the Neo Geo Pocket Color isn't too difficult to emulate, Retroarch has a solid core for it somewhere (though for some reason, performing command inputs is easier on NeoPop than on Retroarch?) As for where to get the ROMs, Global Rule 9 tells me that you should purchase a copy of the game and then make a legally acceptable copy for archival purposes only. I'm sure you get the idea. I'd totally recommend it though, even if only as a distraction. It's a fun little thing to mess around with at least! (And there's also eight unlockable fighters, which is pretty fun.)