1p is basically broken on both due to the insane cpu difficulty
If you walk into AOF1 playing it like SFII, you're going to have a bad time.
But if you attack it like you would an R-Type...
edit: just watched a longplay of AOF1, game still looks great.
The HUGE sprites with the brilliant idea to zoom in and out on the stage.
Awesome idea to show off damage on parts of the character's body that gets damaged heavily.
Exploding the shirt off King and revealing those huge tits that we all masturbated to when we were 13 or 30. Bigger,
badder, better.
Learning how to do moves after completing the bonus stages.
Ryo riding on a cruiser with fucking sandals, which, I will not lie, inspired me to do the same.
The spirit gauge and taunting to decrease their spirit, which means they can't go all Hadouken-crazy every second, was a good fit for the game.
Honestly the music is the only weak point of AOF1, it's not memorable - not bad, not good, just very standard-fare. The B-movie plot adds charm, especially with the "To be continued?".
You know one thing about SNK and Capcom, where Capcom rode on the coattails of SFII's success for years, releasing updates that were practically the same game with only tweaks to balance and whatnot, SNK was creating a ton of different fighting games.
As others have said, it's a great single-player experience. I've read a few times over the years here, "why even play single-player?" but some of us don't have friends to play with yo. AOF1 filled that niche.
double edit: Robert's walking animation is hopping like a rabbit.