Here is the full list of all 12 The King of Fighters 2002 Unlimited Match achievements worth 200 gamerscore.
Clear all Normal Challenges
Unlock all playable characters
Defeat 65 opponents in ENDLESS
Defeat 30 opponents in ENDLESS
Defeat 10 opponents in ENDLESS
Take the perfect Roaring Sphere using Clark
Get a clean hit with Galactica Vanguard using Ralf (available on Practice Mode)
Defeat Ω Rugal and clear TEAM PLAY
Defeat Nameless the challenger
Win a total of 30 RANKED MATCH
Win a total of 10 RANKED MATCH
In TEAM PLAY; defeat any of Krizalid, C.Zero, Zero, or Igniz