ACA NEOGEO THE KING OF FIGHTERS 2000

This is one of the easiest ones yet, in my opinion! Here's what I did:

Pick Joe, King, and whoever for 3rd and 4th. Use this order for matches

When the match starts, jump in towards your opponent and start mashing . Sometimes they will block, but if they don't, you should be able to land anywhere between a 6 - 12 hit combo. The scoring in this game is based on your combos, which makes this perfect, as it has a high combo, but low damage. There is no bonus for perfect, so don't worry about getting hit a couple times. Repeat this as necessary until Joe gets knocked out.

Now that you have King, all you need to do to finish off the match and find out your score is beat your opponent. I chose King because she has a very easy, high damaging basic attack. Simply jump at your opponent and begin mashing . With this, you should kick your opponent in the head, and then get two more quick kicks for a high damage 3 hit combo. Repeat until you win!

I completed this whole game, all three modes and 1000 GS, in 19 minutes using this technique, so hopefully it works for you, too! :)

Just a quick side note - if you end up fighting against short characters, such as Choi or the old, drunk guy, just restart. Joe's punches and King's kicks go right over their heads lol

So, I was reading Exe the Hero's solution, tried it myself but while it works, I don't think it's optimal.

Joe works pretty well but I don't like his inconsistency. Often, the opponent is pushed back during the move and will be in a position where he can either roll and/or punish the attack. Now, it's still a good start to build points.

I think the answer for this achievement is actually Hinako, the little sumo girl from the women team, on the top right, next to Iori.
I know people usually buy the ACA NeoGeo for the relatively easy 1000G and don't necessarily have the background in fighting games but if you can do a quarter circle forward (down, down/forward, forward), you can use her palm strikes (so qcf with A or Y, any punch). Like Joe's flurry, it does relatively low damage but it's way more consistent, as you'll always get 6 hits if the move connects. You will keep the opponent in block or hitstun during the move. It also knocks down the opponent, which means you can trick the AI by doing the move during their wakeup. If you time it right, you can hit them and they won't do anything. Or they'll simply block.

King is also an interesting choice to close up a match. Not because of her Jump D into Close D. But because of her dragon punch... with kick. What is called a dragon is the motion forward, down, down forward, the famous shoryuken motion. With King, doing so with a kick will do a move which will hit the opponent for 12 hits. Now, it does more damage than the two other moves but you want to close a match with King, not 3-0 the opponent with her.

The striker choice doesn't matter, you don't even have to use it.

You can roughly do between 300 to 500 points in one match if you get to play the three characters. You don't even have to change the difficulty.