Bentley Bear is trapped in the Crystal Castles . To get out, he will need to collect all of the gems located throughout the castle. The game is played with an isometric view of the multi-platformed castle. When Bentley collects all of the gems on the current castle, he will move on to the next, more difficult castle. Wandering throughout the castles are a wide variety of dangerous creatures, which Bentley should avoid. From time to time, a magic hat will appear. If Bentley collects the hat, he will temporarily be invincible to the castle's inhabitants.
The gameplay in Crystal Castles is fast-paced and challenging, requiring players to navigate Bentley through the castles while avoiding enemies and collecting gems. The player controls Bentley using the joystick, moving him left and right and jumping over obstacles. As players progress through the game, the castles become increasingly difficult, with more aggressive enemies and fewer gems to collect.