Here is the full list of all 36 The Smurfs 2 - there are The Prisoner of the Green Stone achievements.
Complete the Smurf Forest levels
Complete the Snowy Mountains levels
Complete The Land of Fire levels
Beat the double created by Stolas
Beat the CrystoToad
Beat Stolas
Beat Stolas on «Challenge» difficulty
Completely decrystallize the Smurf Forest levels
Completely decrystallize the Snowy Mountains levels
Completely decrystallize The Land of Fire levels
Find all the replayable challenges
Complete all the Smurf Forest challenges on «Gold» difficulty
Complete all the Snowy Mountain challenges on «Gold» difficulty
Complete all The Land of Fire challenges on «Gold» difficulty
Achieve a «Gold» difficulty for a replayable challenge
Achieve a «Crystal» difficulty for a replayable challenge
Improve the SmurfoMix
Obtain all of Storm’s «Crystal» type improvements
Obtain all of Dimwitty’s «Crystal» type improvements
Obtain all of Brainy Smurf’s «Crystal» type improvements
Obtain all of Handy Smurf’s «Crystal» type improvements
Obtain all of the Green Stone’s «Crystal» type improvements
Obtain all of the «Crystal» type improvements for the StickAll substances
Obtain all of the «Crystal» type improvements for the PushAll substances
Obtain all of the «Crystal» type improvements for the CatchAll substances
Hit a weak spot from more than 80 m when playing Storm
Gather at least 10 CrystoBeasts in the same place when playing Dimwitty
Beat at least 10 CrystoBeasts with the alchemical vial when playing Brainy Smurf
Beat at least 30 CrystoBeasts during the TurboMix when playing Handy Smurf
Completely entangle a CrystoShift with the StickAll substance
Beat a CrystoSlap by shooting it into the void using the PushAll Substance
Target 8 enemies with the CatchAll Substance
Overheat the SmurfoMix once!
Equip a cosmetic
Beat 1000 CrystoBeasts
Collect 1 million essence of nothingness