one day i was talking on discord and moehr mentionned the idea of a hud with 4 sprites to free up the window layer
i liked this idea so i made this hack

tiles $9c-$9f are used for the hud and are updated during vblank
the metroid counter sprite code was altered to display these tiles
be warned that you can no longer see how many metroids are left (in theory you could add it back by replacing the missile count while paused, but i have not done this)

the absence of the window layer during regular gameplay reveals 8 extra scanlines
the camera has been re-centered on samus to compensate for the extra scanlines, lowering samus by 4px
beam no longer despawns when it hits the hud, now despawns when it hits the bottom of the screen
enemy behavior is untouched