On the newest version of the Bubble Bobble pocket core, Bubble Bobble has a black area in the lower right that doesn't seem to obscure the sprites, and Tokio has a black strip up the left side of the playable area that the sprite can fly over. Also, on the Bubble Bobble title screen, part of the logo seems to appear in the bottom left of the screen.
On the newest version of the Bubble Bobble pocket core, Bubble Bobble has a black area in the lower right that doesn't seem to obscure the sprites, and Tokio has a black strip up the left side of the playable area that the sprite can fly over. Also, on the Bubble Bobble title screen, part of the logo seems to appear in the bottom left of the screen.