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