1) Skipping to the endgame

• Brimstone
• Chocolate Milk
• Must play as Blue Baby
• Goal: Blue Baby in the Chest

Rules: Not allowed to pick up any health upgrades and rely entirely on spirit hearts. The only exceptions are if you have guppy's paw and immediately convert HP upgrades into spirit hearts. All item rooms, boss rooms, secret rooms, shops, etc are allowed.

Rational: Northernlion loves brimstone, and he also loves going without heart containers, at least once he's gotten the polaroid. Chocolate milk is there to nerf brimstone enough to provide some challenge, before he can get the damage upgrades to make it viable.

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2) And The Kitchen Sink

• Mom's Contacts
• My Reflection
• Spider Bite
• Spoon Bender
• Ouija Board
• Number One
• Tough Love
• The Common cold
• Wiggle Worm
• Must play as Isaac
• Goal: Satan

Rules: No item rooms, no items that change tears into beams or bombs, etc. All else is fine.

Rational: All of your favorite status effects in one place!

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3) Built to Spill

• The Habit
• 9 volt
• Lemon Mishap
• Holy Water
• Must play as Isaac
• Goal: As far as you can get

Rules: Can't replace your spacebar item, everything else is fair game

Rational: Let's watch Ryan get aquatinted with two of his least favorite items

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I may add more later.

Do you have any suggestions for what I have here? What Are your ideas for challenge runs? Let's hear them in the comments!

Edit: Womp, guess this didn't go over to well, did it?