Here is the full list of all 35 River City: Rival Showdown achievements.
River City Completionist Collected all Achievements!
River City Variant - Complete Protected Nekketsu from Reiho!
River City Weird - Complete Defeated the Double Dragons!
River City - Complete Quelled Yamada's ambitions!
River City - Complete Ended Yamada's dark reign for good!
Cleared Yamada's story!
Cleared Riki's story!
Defeated Alex!
Defeated Roxy!
Learned 5 special moves!
Learned 10 special moves!
Learned 3 ultra moves!
Cleared the Tiger's Den!
Obtained your first unique piece of gear!
Visited 2 Mystery Shops!
Tasted River City's entire menu!
Read your first "Racy Magazine"!
《17》Reached a truce with Senridai!
《32》Defeated the stubborn savage, Kinoshita!
《36》Defeated the spirited speedster, Mochizuki!
《38》Defeated the inhibited instigator, Kobayashi!
《6》Bonded with a peculiar pair from Kagemura?!
《42》Defeated the dynamic duo, Goda and Godai!
《56》Defeated the alley aberration, Makoto!
Reached Level 10
Reached Level 50!
Reached Level 99!
Defeated 1 bonus enemy!
Devoured over 50 rice balls!
Achieved 400,000 points in DDD without losing a single round!
Collected over 500,000 yen!
Defeated Yamada on Easy difficulty!
Defeated Yamada on Intermediate difficulty!
Defeated Yamada on Hard difficulty!
Defeated Yamada on Tough as Nails difficulty!