Pong

Pong is Challenge #35. Isaac starts off with Rubber Cement and Cupid's Arrow. Damage is fixed at 100 and tear delay is fixed at 0.20 . The goal is to defeat ??? in Chest.

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.

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.
- Blue Flies and Blue Spiders damage are not calculated from the fixed challenge damage. Damage is calculated from Isaac's current equipment.
- Blue Fly and Blue Spider damage get calculated on spawn. Existing spawns get their damage to reset to Isaac's base stats x2 when the game is closed and re-opened.
Sacrifice Rooms can be used to skip to the Dark Room. 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.
- This, or another source of damage, is required when dealing with regenerating enemies, like Globins, as you cannot shot a second tear fast enough before they have regenerated.

Good items[ | ]

Shoop da Whoop! is a valuable item since its damage scales with Isaac's damage, one-shotting most bosses.
Bob's Rotten Head is also a very strong item because the poison effect deals triple Isaac's damage.
Rotten Baby's blue attack flies give Isaac a more consistent means of dealing damage.
Tammy's Head, Tear Detonator, Varicose Veins, and Sad Bombs release circles of giant bouncing tears that can clear any room (even bosses) in a few seconds.
Mutant Spider and The Inner Eye provide quadruple and triple shot with no downsides respectively.
Libra provides one of the only means of overriding this challenge's fixed damage and tears. Of questionable benefit, as it provides reasonably high fire rate but rather tame damage. Items that only affect damage or tears (such as Blood of the Martyr or The Sad Onion) apply no change to stats.
Fate's Reward will fire the same high-damage tears at a faster rate than Isaac.
- Similarly, Incubus is a very powerful item as it fires an exact copy of the tear essentially doubling the already high damage. Combine this with BFFS! for that tear to become even larger.
Chocolate Milk 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.
Technology 2 will allow Isaac to fire a very high damage laser without the drawback of the low tear rate.
Succubus is an extremely potent room clearer, since it scales with Isaac's damage.
Finger! scales with Isaac's high starting damage, making this item an effective primary weapon.
Ouroboros Worm 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 Guppy's Head or Box of Spiders will be able to near-instantly kill bosses and clear rooms very fast, as flies do two times Isaac's damage.
Eye of Belial grants homing and piercing tears after hitting one enemy.
Multidimensional Baby doubles tears, which can clear rooms very easily.
Godhead will cover a large portion of the room with its damaging aura. When combined with another item like Ouroboros Worm that speeds up the tear, the entire room may be cleared immediately.
Maw Of The Void can eliminate entire rooms in one go if the circle attack is charged.
The Boomerang will deal double Isaac's damage, for a total of 300 damage, and it recharges in 4 seconds.
Magic Fingers can clear rooms in one go, as it scales with Isaac's damage.
Toxic Shock 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.
Pupula Duplex 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.
The Parasite 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.
Sacred Heart / Spoon Bender/Telepathy For Dummies grant homing, which causes Isaac's tears to hunt down nearby enemies or linger around bosses instead of ricocheting randomly.
Scorpio and The Common Cold are powerful as the poison damage is double Isaac's damage.
Tech.5 will fire lasers as long as the fire button is held, resulting in a large amount of damage at random
Spear Of Destiny deals twice Isaac's damage per tick, defeating enemies and even bosses incredibly easily.
Potato Peeler can be a good choice if Isaac has a lot of heart containers, as the Super Meat Boy that can be created provides a viable alternate source of damage.
Sharp Key scales with Isaac's high damage with no downside. Can potentially kill ??? with only 6 keys.
Eye Drops staggers Isaac's fire rate, which is largely beneficial given this challenge's fixed low fire rate.
Notched Axe/Spirit Sword both ignore tear delay and scale with Isaac's high damage.
Circle of Protection is very effective, as its contact damage and deflected tears scale with Isaac's damage. This is especially useful for clearing stragglers.
Brain Worm causes the tear to snap onto enemies even after several bounces.

Bad items[ | ]

Mom's Knife 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.
- Brimstone, C Section, Monstro's Lung and Tech X 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.
Ipecac 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.
Technology should also be avoided, as the delay between lasers will become very long, and the lasers do not bounce.
ANY damage or tears upgrade will be worthless (except for the aformentioned Libra), and detrimental if they lower other stats in exchange, like for example The Small Rock and Pentagram (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).
Proptosis Will lower damage as the tear travels, without any plus to damage.
The Ludovico Technique and Eye of the Occult, while good at clearing rooms, will make the challenge take longer due to the low damage per tick and big amounts of health some bosses have.

Notes[ | ]

Items that increase damage or tears won't affect Isaac's stats.
- Isaac's damage is fixed for the challenge, but stat adjustments are being processed to calculate blue fly and blue spider damage.
Items that adjust tear range will cause tears to be recalculated: more range means slower fire rate, and vice versa.
Defeating Delirium will also clear the challenge.