The chests in Forever Kingdom are white with bits of gold plating and a black inlay. They can be found in specific areas of each level. Once opened, they will remain opened, and will forever remain opened in the same place they were discovered, even if the player leaves the level and returns.
Occasionally, treasure chests can also be dropped by defeated Mutants. These particular chests behave slightly differently to regular chests: once opened, they will remain opened, as long as the player stays in the particular level he/she was in. If the player leaves the level and comes back, these chests will disappear.