Elland: The Crystal Wars was a Dune game for the GBA that never saw the light of day. Development started in 2001 but the game was cancelled shortly before release. Now the game has been revived as a Kickstarter which has surpassed its goal, and it will be finally coming to the GBA still as a proper cartridge with manual:
https://www.kickstarter.com/projects/elland/elland-the-crystal-warsan-unreleased-gba-game
(https://ksr-ugc.imgix.net/assets/035/528/579/ee29544acab23c11fce26391891a0995_original.png?ixlib=rb-4.0.2&w=680&fit=max&v=1636508840&auto=format&gif-q=50&lossless=true&s=c77fb7ebc7f01ddee24646525feb1b67)