Technically, you can have 4096 sprites, since 0 counts as one. That said, you can only have 512 sprites on screen at once, and you only have a 512x512 pixel space for your sprite sheet. None of these limits are much of a problem though.

thanks i was just experimenting with spdef

This game could work great for making 2D controllable characters like i could make Dante from dmc (2D of course) with over 4096 sprites to use OR EVEN kos mos from xenosaga 2d with 4096 sprites