Main handling routine for the spinning coins that come out of ? blocks.
$029A4F is a fourth of the rolling coin tilemap. This tile is 16x16.
$029A54 is the properties of the rolling coin flying from question blocks.
$029A6B controls the frames, changing to [D0 00] or [EA EA] will cause all 4 frames to only use 1 16x16 tile. Have to combine with $029A4F and $029A6E (same tile) for the complete effect.
$029A6E is three fourths of the tilemap of the rolling coin. These tiles are 8x8, but they're duplicated and placed above each other, making it 8x16.