Pong

Pong is Challenge #35. Isaac start off with and. Damage is fixed at 100 and tear delay is fixed at 0.20. The goal is to defeat ??? in.

Difficulty
The high starting Damage makes this run fairly easy, although keep in mind that with the high tear-delay, tears can only be fired once every 5 seconds.

Make sure to pick after the fight against Mom.

Strategy

 * Keeping Cupid's Arrow in mind, try to hit as many enemies with the initial shot as possible since while the tear is midair Isaac cannot shoot any more tears until the cooldown is up.
 * Before entering the next room, make sure that the current tear is no longer flying, since Isaac may not be able to shoot a tear upon entering a new room.
 * There is not a need to take any damage ups, so if given the choice, pick speed or Health ups.
 * All items that generate flies are extremely useful, due to fixed high damage.
 * Sacrifice Rooms can be used to skip to the . Beating The Lamb there will count as clearing the challenge.
 * Thanks to the huge damage stat, Isaac can easily reach Boss Rush if reached in time. But while Boss Rush can provide extremely beneficial items, most bosses won't die in a single hit (and damage cannot be increased to one-shot them), resulting in Isaac having to avoid several attacks to fire the next tear. It may be better to skip the Boss Rush to avoid taking unnecessary damage.
 * Luring enemies into the bouncing tear may be a viable strategy, especially if it is stuck somewhere.
 * Purposely making the tear stuck (e.g. by shooting it against a wall directly, making it bounce back and forth) might be viable situationally (e.g. Larry Jr. or any fight, where the boss is stationary, especially when this stationary enemy is in the center of the room.

Good items

 * is a valuable item since its damage scales with Isaac's damage, one-shotting most bosses.
 * is also a very strong item because the poison effect deals triple Isaac's damage.
 * 's blue attack flies give Isaac a more consistent means of dealing damage.
 * ,, and are very valuable as the storm of giant bouncing tears can clear any room (even bosses) in a few seconds.
 * and also provide a big help since tear delay is fixed.
 * is a very valuable item, as it will balance all stats out, even the stats fixed by the challenge, giving Isaac very high and balanced stats, making the challenge effectively trivial.
 * will fire the same high-damage tears at a faster rate than Isaac.
 * Similarly, is a very powerful item as it fires an exact copy of the tear essentially doubling the already high damage. Combine this with  for that tear to become even larger.
 * is an extremely powerful item that will allow Isaac to quickly fire small but powerful tears, or charge up to fire a room size tear that will rapidly bounce off all enemies in the room.
 * will allow Isaac to fire a very high damage laser without the drawback of the low tear rate.
 * is an extremely potent room clearer, since it scales with Isaac's damage.
 * helps when getting hit, as it will trigger the Tammy's Head effect each time.
 * scales with the high starting damage, making this item a perfect primary weapon.
 * n can make this run trivial as the tear's high speed and travel rate can have it cover the entire room before it bursts.
 * Items that give flies or spiders like or  will be able to near-instantly kill bosses and clear rooms very fast, as flies do two times Isaac's damage.
 * grants homing and piercing tears after hitting one enemy. This makes the run very easy.
 * doubles tears, which can clear rooms very easily.
 * will cover a large portion of the room with its damaging aura. When combined with another item like n that speeds up the tear, the entire room may be cleared immediately.
 * can eliminate entire rooms in one go if the circle attack is charged.
 * will deal double Isaac's damage, for a total of 300 damage, and it recharges in 4 seconds.
 * can clear rooms in one go, as it scales with Isaac's damage.
 * Magic Fingers no longer scales with the full damage, being fairly mediocre.
 * allows Isaac to clear most rooms upon entering them, as it will deal double Isaac's damage (for 200 in total) to every enemy in the room upon entering.
 * Isaac's tears become a huge arc covering more than half of the width of a typical room allowing for an easy run while one-shotting bosses.
 * Isaac's tears split into smaller ball-shaped tears upon hitting enemies, causing the room to quickly fill with bouncing tear shots that can quickly clear a room.
 * allows you to stagger your shots, meaning you can fire more often and sometimes simply fire two shots at once.
 * allows you to control your tears making hitting enemies more reliable.
 * swings scale with your damage without any delay, making it a surprisingly good weapon.
 * is very effective, as its contact damage and deflected tears scale with Isaac's damage. This is especially useful for clearing stragglers.

Bad items

 * should be avoided; despite enormous damage, it will take a long time to charge for any meaningful distance, so Isaac will be essentially reduced to melee range.
 * , and  should also be avoided. Although the attack will probably be enough to destroy any enemy or boss, Isaac is defenseless during the lengthy charge time. Tech X also loses the benefit of bouncing attacks.
 * should also be avoided. The tears will not bounce anymore, and due to the great height of the tears, these will pass over the enemies, being very difficult to hit.
 * should also be avoided, as the delay between lasers will become very long, and the lasers do not bounce.
 * and (if offered by a deal with the Devil) should be avoided; the former will only lower Isaac's speed while the latter will only result in a loss of a Heart container(s).
 * Will lower damage as the tear travels, without any plus to damage.
 * Since your lowest stat will, most likely, be Tear Delay and that stat is fixed, there will be no stat change. Will still drop coins/bombs/keys like normal.

Trivia

 * The challenge's name is a reference to the game Pong.