Creator/{{Atari}} released this isometric video game in 1983. The player uses a trackball and a jump button to control Bentley Bear as he collects gems along the paths of the castles. Wearing the magic hat allows Bentley to kill the WickedWitch, Berthilda. Her gem eaters are vulnerable only while they are eating. Bentley can jump over the trees to stun them for a short time. Other enemies cannot be killed, so Bentley must avoid them. Secret warps take Bentley to higher levels.

A level ends when all the gems are collected. If Bentley gets the last gem, the player gets bonus points. Unlike most video games of the time, ''Crystal Castles'' actually has an [[http://www.vgmuseum.com/end/arcade/c/crycas.htm ending]].

Bentley made an appearance as a playable character in ''Atari Karts'' for the UsefulNotes/AtariJaguar. Afterwards Bentley seemed to disappear from existence barring ''Crystal Castles''[='=] appearance in a few compilations. Years later, a homebrew FanSequel in the form of a PlatformGame for the UsefulNotes/Atari7800 titled ''Bentley Bear's Crystal Quest'' from developer [=PacManPlus=] was announced. That game is planned to work with the Atari 7800 XM to give the system an increased amount of memory and, most notably, more advanced sound hardware through the Pokey audio chip--pushing the system beyond its limits. Needless to say, the 7800 XM has spent quite an amount of time in DevelopmentHell, and it is unknown when it, along with ''Crystal Quest'', will be released to the public, if ever.
!!This game provides examples of:
* BearyFriendly: Bentley Bear himself.
* BeeAfraid: If Bentley stands still too long, a swarm of bees will appear.
* EndlessGame: Averted. In the early 1980s, when most games just went on until the difficulty outdid the player or the game [[KillScreen went awry]], its inclusion of a proper ending was quite unusual.
* ExtremeOmnivore: The Gem Eaters very much do ExactlyWhatItSaysOnTheTin.
* InvincibilityPowerUp: The Magic Hat makes Bentley invulnerable for a few seconds.
* IsometricProjection: Specifically, this game uses trimetric projection.
* SpeciesSurname: Bentley ''Bear''.
* SymbolSwearing: Die on your last life and Bentley shouts "#?!" before he rises off-screen.
* WarpZone: The first, third, and fifth levels have a secret warp that takes the player to the next odd-numbered level, triggered by jumping in a specific corner of the level, sometimes while wearing the Magic Hat.
* WhenTreesAttack: The Nasty Tree enemy.
* AWinnerIsYou: The text shown after level 10:
-->I give up: you win
-->You must be very good