The increased tear height and decreased range results in overall slightly less firing distance.
Occasionally, firing tears will cause Isaac to charge an attack with his head pulsating with a red color. After the attack has charged up, the fire button can be released to fire a kidney stone that deals extra damage while piercing enemies and walls, and to fire a barrage of tears afterwards.
This effect occurs approximately every 25 seconds.
Isaac won't be able to fire tears normally until the kidney stone has been fired.
The kidney stone has approximately twice the range of normal tears.
The tears fired afterwards are a bit inaccurate and can be fired slightly to either side.
The barrage will continue for its full length between Rooms, as will the state of charging the attack instead of firing tears.
When Isaac has half a heart left, the urine that appears underneath Isaac upon entering rooms will be changed to red.
Complete challenge #29 ( The unlock is bugged and actually unlocks Blank Rune)