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.
However, there is a universal pain point for fans of the console: Standard GameCube ISOs range from 1.35 GB to 1.46 GB per disc. When you try to build a full library or transfer games to a handheld device like the Steam Deck, Retroid Pocket, or Ayaneo, storage space vanishes instantly. 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