TEARKILL

Mankind is dead. Blood is fuel. Tears are ammo.

The Cyber Grind turns into a run of The Binding of Isaac. Your guns are gone: you cry Isaac's tears, pick up Isaac's items between waves, fight Isaac's monsters alongside ULTRAKILL's, and pay the devil in heart containers.

Pick your machine

• V1: high damage, slow tears that fly fast. Feedbacker only. Right click tosses a coin: shoot it to ricochet, and your items change what the ricochet does. Starts with 5 heart containers.
• V2: cries blood, and cries it fast. Knuckleblaster and Whiplash. Key 1 throws a meat hook that catches an enemy, swings it through the crowd and hurls it. Blood dash, and a rage last stand. She's still mad about the arm.
• Gabriel: no tears, just two holy swords. Slash, throw Splendor, and use keys 1 to 5 for the spear, axes, teleport, summoned swords and ENOUGH. Fill his judgement to 500,000 and his second phase begins once he's down to his last heart: The Death of God's Will plays, he flies, nothing can touch him, and his abilities recharge every second.

The run

• 120 Isaac items with their real stats and effects: Brimstone, Mom's Knife, Tech X, Epic Fetus, familiars, active items and more. On top of those, 34 synergies with V1's coins and Gabriel's swords, and 9 transformations (Guppy, Beelzebub, Spun, Yes Mother? and the rest).
• An item every 5 waves, a boss every 10. Bosses come from both games: Monstro, Gurdy, The Widow and others from Isaac, Swordsmachine, Mindflayer and Ferryman from ULTRAKILL. Mom waits at wave 30 and Mom's Heart at wave 50.
• Devil and angel deals after every boss. Devil deals cost heart containers.
• Coins and a shop, bombs and keys, golden chests, and champion enemies that get more common the longer you last.
• Isaac's hearts:
  • Red containers refill with blood, as in ULTRAKILL.
  • Soul and black hearts never refill.
  • A black heart that breaks wipes out every enemy that isn't a boss.
• Isaac's HUD, curses and death page, which shows what killed you and everything you were carrying.

Controls

• Left click: cry tears (Gabriel: slash).
• Right click: V1 tosses a coin, Gabriel throws his sword.
• 1: V2's meat hook. Gabriel uses keys 1 to 5 for his abilities.
• Q: active item.
• E: throw a bomb.
• Dash: V2's blood dash, Gabriel's blink.
• F3: enemy health bars and damage numbers (debug setting).

What you need

• ULTRAKILL.
• The Binding of Isaac: Rebirth with Afterbirth+ or Repentance, on Steam.

Melty installs BepInEx for you. The mod reads art, sounds and data from your own copies of both games while it runs, so no game files are included.

Credits

ULTRAKILL is by Arsi "Hakita" Patala and New Blood Interactive. The Binding of Isaac: Rebirth is by Edmund McMillen and Nicalis. The mod is loaded and patched with BepInEx and Harmony (MIT). This is a fan mashup, not affiliated with or endorsed by either game's makers.