Here is the full list of all 47 Splasher achievements.
Lasers are my calling card
I get knocked out, but I get up again!
A good Potatrooper is a drowned Potatrooper!
Get Water Stickink
Get your first Gold Medal in Time Attack
A good Potatrooper is a dead Potatrooper!
Fries anyone?
A friend in need is a friend indeed
Get your first Medal in Time Attack
It's all going splendidly
Jump and you're history
Rescue all the Splashers from a level in Standard mode
Get Water
Complete the game in Standard mode
Rescue all 154 Splashers in Standard mode
Complete a level without dying
Go Splashteam
Get Bouncink
You should have held that door!
Give yourself to the Dark Side
You're never going to keep me down!
Off to a flying start
A bird with two stones
All in a good cause
Mashed Potatroopers
Why is it always me?
Complete all the quarantine areas
You rang milord?
A close shave
Complete a level without jumping
699
At least I'm not the only one
Right time, right place
Two Splashers in the same place? Impossible.
Get your first Platinum Medal in Time Attack
Complete a Selfish Speedrun
Complete a Standard Speedrun
Complete a Gotta Catch'em All Speedrun
Get your first Medal in Speedrun
Get your first Gold Medal in Speedrun
Get your first Platinum Medal in Speedrun
Complete a Speedrun without dying a single time
Get all the Bronze Medals in the game
Get all the Silver Medals in the game
Get all the Gold Medals in the game
Get all the Platinum Medals in the game
Get all the Achievements. After that, you are definitely one of the best players on the planet, perhaps even the best ever! Continue to prove it in the leaderboards!