The extra life has some extra shading in the earlier builds - this is also how it looked in the previous two titles, but the golden palette X gets with the Hyper Chip doesn't work well with the older graphic, necessitating a sprite change. This unique orange palette was added in a later version. X's fourth charge level uses the third charge level's palette in the August builds. The preview for Neon Tiger's stage is missing in the August prototypes, but the palette still exists. The preview for Tunnel Rhino's stage is missing in the August prototypes, but the palette still exists. The preview for Gravity Beetle's stage changed the clouds and added a setting sun in the final. The preview for Crush Crawfish's stage added some shading to the sky and darkened the lines on the building in the final. The preview for Blizzard Buffalo's stage looks completely different, aside from the same graphical layout.
Blast Hornet, Toxic Seahorse, and Volt Catfish are identical to the final. While the code for displaying the stage previews has mostly been removed (some of the subroutines still exist), the preview images can still be found in the ROM (except for Tunnel Rhino & Neon Tiger, see below).
