Here is the full list of all 24 Lupinball achievements.
You won a round that ended while the screen was upside down
You fired the most shots out of everyone, and still lost
You won a round where you shielded over twice as often as you shot (must shoot at least once)
You won a round without firing a single shot
Everyone got shocked/stunned at least once in the same round
In a 4-player round, all your foes were blocked by the Orb Blocker when they died
You won a round where over 25 shots were fired
Complete a 5-point 4-player local multiplayer match
Fire 1,000 shots
Play 1 online match
Play 5 online matches
Play 10 online matches
Play 20 online matches
Play 30 online matches
Play 50 online matches
Play 75 online matches
Play 100 online matches
Play 150 online matches
Play 200 online matches
Play 300 online matches
Play 500 online matches
Play 777 online matches
Play 1,000 online matches
Clean-sweep an online match (ie. win a match while all your opponents get zero points)