Solar System

**Solar System** is challenge #6. Isaac starts this challenge with , , , and . Isaac will also be blindfolded. The goal is to defeat Mom's Heart/ It Lives. This Challenge is available after unlocking Transcendence.

## Difficulty

* As Isaac is blindfolded, Isaac cannot use tears, and must rely entirely on Distant Admiration, Forever Alone, and bombs to deal damage.

## Strategy

* Because Isaac starts with 3 Fly items, he will also begin the challenge as . This allows Isaac to amass a large number of friendly flies on the Basement floors.
* The orbiting attack flies can be quite powerful, especially Distant Admiration when used properly. This will require optimization of Isaac's movement to maneuver into position to deal damage, as the flies are constantly moving, and avoid damage simultaneously.
	+ can fix the position of the flies around Isaac, somewhat alleviating this.
* Enemies that explode on death should only be targeted with Forever Alone, as destroying them with Distant Admiration will result in Isaac getting caught in their explosions.
* provides consistent per-room damage output that scales with your damage stat, and can appear in Curse Rooms.
* Shops can carry  and , the former of which affects the damage of the orbiting attack flies and the latter of which affects the damage of the blue flies spawned from Beelzebub as well as the size of the orbiting attack flies.
* and  are good items to buy since they slow enemies down, although caution should be exercised with Broken Watch.
	+ 's speeding up effect can be cancelled by exiting the run and continuing.
* Obtaining  makes the challenge trivial as Isaac's orbiting flies still deal damage while Isaac is invulnerable. Obtaining it is highly unlikely, since there are no Treasure Rooms present.
* Obtaining  or  grants a full circle of projectile-blocking orbitals around Isaac.
	+ Collecting two Cubes of Meat grants a tear-firing familiar that is not affected by the blindfold.
	+ Obtaining  makes The Harbingers easier to find, allowing Cube of Meat and Ball of Bandages to be amassed more easily.
* It is not advised to reshuffle Isaac's items. As this will not remove Isaac's Blindfolded status, it is possible to reroll items in such a way that Isaac's orbitals are rerolled into useless items, thus making the run impossible to complete.
* Obtaining the , , , or  can make killing Mom and Mom's Heart/ It Lives much easier.
* Devil Room deals such as , , and  will be ineffective due to Isaac's blindfold.
	+ now functions despite the Blindfolded status, making this a very valuable item for the challenge.
* is a useful purchase from the shop as it has a chance to freeze enemies, allowing Isaac to safely use the attack flies against them for the duration of the freeze.
* Transcendence and other flight items are useless in this challenge as the  transformation grants flight by default.
* Obtaining  can be handy for defeating bosses, due to its damage and poison effect. It can also be used to break poop or golden poop to gain health, coins, or bombs.
* electrifies the orbiting flies, dealing extra damage and allowing Isaac to destroy Fire Places and Poops.
* helps damage non-flying enemies and bosses.
	+ Black Powder is now effective on all enemies and bosses, making it a reliable source of damage without the precision required to deal damage using Isaac's orbiting flies, provided there is room to draw closed shapes.
* acts as a replacement for Isaac's tears, thus indirectly removing Isaac's Blindfolded status.
* can charge and fire regardless of the Blindfolded status, providing Isaac with an easy way to deal damage.
* can be used to great effect as it can permanently stop the movement of all enemies in every other room. Pairing this with items that help with recharging activated items, mainly , can guarantee victory.
* It is heavily advised not to use , as it removes both of Isaac's damaging orbital familiars. If no alternative source of damage has been obtained by then, or rewarded by Sacrificial Altar itself, the run will be rendered impossible.

## Unlockable achievements

* Rune of Perthro - Complete **Solar System (challenge #6)**.

## Trivia

* The challenge is a reference to the real-world Solar System; Isaac represents the Sun and his flies represent planets.