If you are having problems animating the background, then here is an easy way to do it.

 - you need some loop based counter (goes from 0-3, loops at 4)
 - leave the last two bits on the each tile blank.
    - ex.  1st = %00000000
           2nd = %00000100
           3rd = %00001000
           4th = %00001100    ; and so on
 - to make this work, in the tilemap routine, where you draw the tiles,
   you get the tile ID from the map and load it into register B
>
 ld b,(hl)
 ld a,(map_animation_offset) ; from 0-3
 add a,b  ; a = animated tile
>
 - remember that each tile requires 4 sprites (4 frames of animation)
   so space them out