These square "3D" balls can't be shot, but you can drag them around. You use them to build structures in the "3D" levels.

<ball name="Pixel"
      shape="rectangle,32,32"
      walkforce="500" 
      mass="30"
      towermass="3.0" 
      strands="2" 
      walkspeed="0.1"
      climbspeed="2.0"
      speedvariance="0.2"
	  detachable="false"
      blinkcolor="0,0,0"
      jump="0.0,0.3"
 
	  burntime="0.1"
      detonateforce="0.01"
      detonateradius="10"
 
	  explosionparticles="BallExplode_ISH"
      >
 
	<!-- For the marker, we need to be able to specify images for each player -->
  <marker	drag="IMAGE_BALL_PIXEL_DRAGMARKER_P1"
			detach="IMAGE_BALL_PIXEL_DRAGMARKER_P1"
			rotspeed="-2"/>
 
 
  <particles id="ish_sleepyZzz" states="sleeping" overball="true" />
  <particles id="ish_smallfire" states="onfire" overball="true" />
 
  <strand type="spring" 
          image="IMAGE_BALL_PIXEL_ARM" 
          inactiveimage="IMAGE_BALL_PIXEL_ARM" 
          springconstmin="9" springconstmax="9" 
          dampfac="0.9" 
          maxlen2="140" maxlen1="200" 
          maxforce="600"
          minlen="100"
 
		  burntimage="IMAGE_BALL_PIXEL_ARM" 
          ignitedelay="0"
          burnspeed="3"
          fireparticles="ish_smallfire"
          />
 
  <splat image="IMAGE_BALL_PIXEL_SPLAT1,IMAGE_BALL_PIXEL_SPLAT2"/>
 
  <part name="body"
        layer="0"
        rotate="true"
        x="0" y="0"
        image="IMAGE_BALL_PIXEL_BODY"
        stretch="24,1.75,0.65"
        scale="0.5"
        />
 
 
 
  <!-- walking animations -->
  <sinvariance freq="1.2" amp="0.1" shift="0.0">
    <sinanim part="lefteye,righteye" state="walking" type="translate" axis="y" freq="2.0" amp="2"   shift="0" />
    <sinanim part="righteye"         state="walking" type="translate" axis="x" freq="2.0" amp="0.5" shift="0" />
    <sinanim part="lefteye"          state="walking" type="translate" axis="x" freq="2.0" amp="0.5" shift="0.5" />
  </sinvariance>
 
  <!-- standing animations -->
 
  <!-- dragging animations -->
  <sinvariance freq="1.5" amp="0.5" shift="0">
    <sinanim part="righteye" state="dragging" type="translate" axis="x" freq="1.0" amp="-1" shift="0" />
    <sinanim part="lefteye"  state="dragging" type="translate" axis="x" freq="1.0" amp="1" shift="0" />
  </sinvariance>
 
  <!-- tank state animations -->
  <sinvariance freq="0.3" amp="0.02" shift="0.0">
    <sinanim part="righteye"         state="tank" type="translate" axis="x" freq="1.0" amp="0.2" shift="0" />
    <sinanim part="lefteye"          state="tank" type="translate" axis="x" freq="1.0" amp="0.2" shift="0.5" />
  </sinvariance>
  <sinvariance freq="0.1" amp="1" shift="0.0">
    <sinanim part="lefteye,righteye" state="tank" type="translate" axis="y" freq="0.4" amp="3" shift="0"   />
  </sinvariance>
 
 
  <!-- Sound FX -->
 
  <sound event="marker"       id="SOUND_BALL_PIXEL_CHIRP01,SOUND_BALL_PIXEL_CHIRP02,SOUND_BALL_PIXEL_CHIRP03,SOUND_BALL_PIXEL_CHIRP04"/>
  <sound event="pickup"       id="SOUND_BALL_PIXEL_CHIRP01,SOUND_BALL_PIXEL_CHIRP02,SOUND_BALL_PIXEL_CHIRP03,SOUND_BALL_PIXEL_CHIRP04"/>
 
  <sound event="drop"         id="SOUND_BALL_PIXEL_CHIRP01,SOUND_BALL_PIXEL_CHIRP02,SOUND_BALL_PIXEL_CHIRP03,SOUND_BALL_PIXEL_CHIRP04"/>
  <sound event="throw"        id="SOUND_BALL_PIXEL_CHIRP01,SOUND_BALL_PIXEL_CHIRP02,SOUND_BALL_PIXEL_CHIRP03,SOUND_BALL_PIXEL_CHIRP04"/>
 
  <sound event="bounce"       id="SOUND_BALL_PIXEL_CHIRP01,SOUND_BALL_PIXEL_CHIRP02,SOUND_BALL_PIXEL_CHIRP03,SOUND_BALL_PIXEL_CHIRP04"/>
  <sound event="land"         id="SOUND_BALL_PIXEL_CHIRP01,SOUND_BALL_PIXEL_CHIRP02,SOUND_BALL_PIXEL_CHIRP03,SOUND_BALL_PIXEL_CHIRP04"/>
 
  <sound event="attach"       id="SOUND_BALL_PIXEL_CHIRPUP01,SOUND_BALL_PIXEL_CHIRPUP02,SOUND_BALL_PIXEL_CHIRPUP03,SOUND_BALL_PIXEL_CHIRPUP04"/>
  <sound event="attachcloser" id="SOUND_BALL_PIXEL_CHIRPUP01,SOUND_BALL_PIXEL_CHIRPUP02,SOUND_BALL_PIXEL_CHIRPUP03,SOUND_BALL_PIXEL_CHIRPUP04"/>
 
  <sound event="death"        id="SOUND_BALL_PIXEL_CHIRP01,SOUND_BALL_PIXEL_CHIRP02,SOUND_BALL_PIXEL_CHIRP03,SOUND_BALL_PIXEL_CHIRP04"/>
  <sound event="deathfall"    id="SOUND_BALL_PIXEL_CHIRP01,SOUND_BALL_PIXEL_CHIRP02,SOUND_BALL_PIXEL_CHIRP03,SOUND_BALL_PIXEL_CHIRP04"/>
 
  <sound event="ignite"       id="SOUND_BALL_PIXEL_IGNITE01,SOUND_BALL_PIXEL_IGNITE02,SOUND_BALL_PIXEL_IGNITE03,SOUND_BALL_PIXEL_IGNITE04"/>
  <sound event="detonate"     id="SOUND_BALL_PIXEL_POP01,SOUND_BALL_PIXEL_POP02,SOUND_BALL_PIXEL_POP03,SOUND_BALL_PIXEL_POP04,SOUND_BALL_PIXEL_POP05,SOUND_BALL_PIXEL_POP06,SOUND_BALL_PIXEL_POP07"/>
 
</ball>