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 Wicked Witch, 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 ending.
Bentley made an appearance as a playable character in Atari Karts for the Atari Jaguar. Afterwards Bentley seemed to disappear from existence barring Crystal Castles' appearance in a few compilations. Years later, a homebrew Fan Sequel in the form of a Platform Game for the Atari 7800 titled Bentley Bear's Crystal Quest from developer PacManPlus was announced. After some time in Development Hell, it was ultimately released on AtariAge's store in 2017.
This game provides examples of:
- Beary Friendly: Bentley Bear himself.
- Bee Afraid: If Bentley stands still too long, a swarm of bees will appear.
- Endless Game: Averted. In the early 1980s, when most games just went on until the difficulty outdid the player or the game went awry, its inclusion of a proper ending was quite unusual.
- Extreme Omnivore: The Gem Eaters very much do Exactly What It Says on the Tin.
- Invincibility Power-Up: The Magic Hat makes Bentley invulnerable for a few seconds.
- Isometric Projection: Specifically, this game uses trimetric projection.
- Species Surname: Bentley Bear.
- Symbol Swearing: Die on your last life and Bentley shouts "#?!" before he rises off-screen.
- Warp Zone: 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.
- When Trees Attack: The Nasty Tree enemy.
- A Winner Is You: The text shown after level 10:I give up: you winYou must be very good[[note:The last words vary depending on how many lives you have left.]]