Here is the full list of all 27 Nickelodeon: Kart Racers achievements worth 1,000 gamerscore.
Co-operative special attack for the first time.
Compete 10 times in each Arena mode.
Win all Cups in Normal mode.
Win at the last second in Grand Prix Mode.
Win all Cups in Expert mode.
Unlock every upgrade in the store.
Win all Cups in easy mode.
Win 9 victory laps.
Activate the Slime in all the locations.
Break 5 objects in a single race using boost.
Put in the miles on the jetski.
Win with all racers.
Win a Cup in Expert mode.
Play as each racer at least once.
Use custom power ups for all the racers.
Win a Cup in Normal mode.
Find a shortcut.
Compete in the Arena for the first time.
Modify your kart for the first time.
Beat your record for first time.
Take down at least 3 opponents in a single race.
Win a Cup in easy mode.
Win a victory lap.
Win your first race.
Use boost for the first time.
Activate the Slime valve for the first time.
Use a custom power up for the first time.