Here is the full list of all 25 Gimmick! Special Edition achievements.
Broke the 30000 SCORE
Broke the 10000 SCORE
Got the hidden item in stage 1.
Broke the 60000 SCORE
Broke the 100000 SCORE
I beat Ponta.
Defeated the warrior Ohagi.
I defeated the soldiers guarding the castle.
I beat the wizard 'Ohagi'
I beat the wizard 'Ohagi2'
Stage 1 cleared.
Stage 2 cleared.
Stage 3 cleared.
Stage 4 cleared.
Stage 5 cleared.
Stage 6 cleared.
Stage 7 cleared.
Got the hidden item in stage 2.
Got the hidden item in stage 3.
Got the hidden item in stage 4.
Got the hidden item in stage 5.
Got the hidden item in stage 6.
Normal End achieved.
True End achieved.
Unlocked all the achievements.