Important note: Due to the multi-cart nature of this game, do not use the "reset cart" menu option. All that will do is corrupt the data loaded from another cartridge and make the whole system crash.
A massively multi-cart Mario Party type of game. Currently an early proof-of-concept tech-demo type of thing and not actually "playable".
The character select can be huge because every character exists in its own "sprite blueprint" cart and gets chainloaded compressed into RAM when the game starts, followed by the game board or game mode (eg. a minigame select free-play menu) cart which drives the rest of play. The board/mode itself (and any minigames it loads into) decompress only the specific sprites they need into the active sprite sheet for use in play. Some minigames might only use the sideways character sprites because they're 2D. Some might use tiny Jelpi-style sprites for players. Some might opt to use player portraits instead of world sprites. And so on.
The sprite blueprint system supports multi-part sprites (in this case Nora's head is separated from her body in all but the portrait sprites) made of parts which are independently offset, vertically and horizontally flipped, and palette-remapped (including primary and secondary "special colors" which might be remapped for duplicate players or special events), and all that data is transferred between carts so the sprites, colors, and character names are consistently recreated.