Here is the full list of all 42 ROBO OH achievements.
Win a round in Story Mode using a Super attack
Win a perfect round in Story Mode
Win a round in Story Mode before the clock goes under 70
Spend 10 points upgrading a robot in Story Mode
Defeat MAXCYBER in Story Mode
Perform a combo that deals 300 or more damage
Perform a combo that deals 8 or more hits
Complete Story Mode without upgrading
Complete Story Mode with all characters on any difficulty
Complete Story Mode with all characters on Maniac difficulty
Complete Story Mode with RINGKING on any difficulty
Complete Story Mode with RINGKING on Maniac difficulty
Complete Story Mode with MEGASTAR on any difficulty
Complete Story Mode with MEGASTAR on Maniac difficulty
Complete Story Mode with NEKOGAMI on any difficulty
Complete Story Mode with NEKOGAMI on Maniac difficulty
Complete Story Mode with DRAGONOH on any difficulty
Complete Story Mode with DRAGONOH on Maniac difficulty
Complete Story Mode with MASAMIOH on any difficulty
Complete Story Mode with MASAMIOH on Maniac difficulty
Complete Story Mode with AUTOFIVE on any difficulty
Complete Story Mode with AUTOFIVE on Maniac difficulty
Complete Story Mode with GRANDSKY on any difficulty
Complete Story Mode with GRANDSKY on Maniac difficulty
Complete Story Mode with YUMELODY on any difficulty
Complete Story Mode with YUMELODY on Maniac difficulty
Complete Story Mode with MAXCYBER on any difficulty
Complete Story Mode with MAXCYBER on Maniac difficulty
Complete Story Mode with HEAVYTEX on any difficulty
Complete Story Mode with HEAVYTEX on Maniac difficulty
Complete Story Mode with UCHUZINE on any difficulty
Complete Story Mode with UCHUZINE on Maniac difficulty
Complete Story Mode on any difficulty with 30000 or more points earned
Complete Endless mode on any difficulty with 11 or more foes defeated
Complete Story Mode with SUTEKISS on any difficulty
Complete Story Mode with SUTEKISS on Maniac difficulty
Complete Story Mode and become The Alien King on any difficulty
Complete Story Mode and become The Alien King on Maniac difficulty
Complete Story Mode and become The Dark King on any difficulty
Complete Story Mode and become The Dark King on Maniac difficulty
Complete the hidden challenge in Story Mode on any difficulty
Complete the hidden challenge in Story Mode on Maniac difficulty