The competitive Melee community popularized the 1.02 - Reduced Lag (20XX) and Slippi NKit ISOs, which are often compressed to under 400MB. These are legal patch files distributed for modding.
Enter the holy grail of modern emulation: gamecube rom highly compressed portable
For general libraries, you will find "GameCube ROM Packs" on archive sites. However, quality varies wildly. Many "highly compressed" packs are actually because they used old CISO formats that desync audio, or they scrubbed critical data. The competitive Melee community popularized the 1
For nearly two decades, the Nintendo GameCube has enjoyed a renaissance. What was once a "purple lunchbox" overshadowed by the PlayStation 2 is now a retro-gaming gem, home to classics like Super Smash Bros. Melee , The Legend of Zelda: The Wind Waker , and Eternal Darkness . However, quality varies wildly
Disclaimer: Emulation laws vary by region. Always dump your own BIOS and game files from media you own. Do not download ROMs from torrent sites, as they often contain malware disguised as "compression tools."