The outside of buildings does not match the inside layout.
When the Boy, Girl, and Sprite people want to travel fast, they pay and go in a cannon by the cannon man, when they are fired into the air they land very hard and quickly get up. It wouldn't be possible for them to survive the fall let alone get back up, they would've died very instantly upon impact. They should've had their parachutes to slow down their fall or a magic spell to levitate slowly down on the ground which is much safer than falling and hitting the ground upon impact which would've cause a game over message to happen but the game continues on as normal.
Despite the Super Nintendo Entertainment System having 8 channels of sound, the music noticeably cuts out during fighting.
Spelling and punctuation mistakes in in-game text.
A glitch allows enemies to sometimes be hit if they are behind thin walls.
Whenever the Boy has something done to his sword such as reforming, it never leaves his hand even though the blacksmith can be heard reforming it on his anvil.
Some houses have a water-wheel but no mill within.
The soldier guarding the treasure in Pandora's castle disappears without a trace when the king gives leave for the Player to take the treasure.
Smiths are able to forge weapons even without their forges.