The rainbow jewels have been abducted from the temple of the rainbow colors, and the world will slowly bleach out if you can't retrieve them.
The hunt for the lost rainbow jewels is a single player RPG with an isometric (2.5D) display. It's written in Java and uses the LWJGL library for display and sound.
News: In early 2015, I started a new project, called "Imp City", using the Jewelhunt codebase to implement a new game, kind of a crossover of a Settlers type game and Dungeon Keeper...