quick summary : (video still interesting) - optimize sprites as 8x8 tiles, use symmetry - reuse sprites / tiles with different palettes - define levels as me

quick summary : (video still interesting) - optimize sprites as 8x8 tiles, use symmetry - reuse sprites / tiles with different palettes - define levels as metatiles of 32x32 made of 4x4 tiles - set levels as symmetric, use high bit of metatile indices to define rotation of each metatile line. - delta-encode hard mode wrt standard mode