Here is the full list of all 26 PictoQuest achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Read the tutorial
Reach 0 gold
Loose 10 times
Finish all quests
Beat Moonface
Reach 5000 gold
Beat the mountain boss
Beat the mangrove boss
Beat the seaside boss
Buy all life extensions
Beat the desert boss
Use the ice orb
Use the thunder orb
Beat the cave boss
Beat the swamp boss
Make 20 mistakes
Beat the forest boss
Use the fire orb
Beat the plains boss
Use a potion
Have a full inventory
Beat the village boss
Finish a three-monster grid
Finish a two-monster grid
Finish a one-monster grid
Finish the first grid