>I have started to display around 70 sprites on screen at once, most of
>them are size 16x16. If I display more than 70 odd, sprites start to
>disappear randomly.

Are the sprites disappearing completely, or just parts of them? At a
guess, with the information supplied, I would say that you're exceeding
the display limitations for sprites on a raster line. The GBA is only
capable of displaying up to 76 16 pixel wide sprites on any given raster
line. Any more than this and the data won't be displayed. Are the
sprites in fairly close Y proximity on screen?

FGL