Killcraft puts a Minecraft player into ULTRAKILL’s levels. It’s built on SkyCraft: a real Minecraft runs hidden in the background, and ULTRAKILL draws its player, HUD, blocks and items. This guide follows v1.0.1 from goonsn/Killcraft. New to mods? Read Start here first.
1. What you need
- ULTRAKILL on Steam.
- BepInEx 5 for ULTRAKILL:
BepInEx_win_x64_5.4.x.zipfrom the BepInEx releases, unzipped into the ULTRAKILL folder. Start the game once so BepInEx sets itself up. - A Microsoft account that owns Minecraft: Java Edition.
You don’t need SkyCraft or Skyrim. The Killcraft zip already includes SkyCraft’s Minecraft bundle (SkyCraft-Minecraft.zip, a portable Prism Launcher with the SkyCraft instance). Minecraft and Java download by themselves the first time.
2. Install
- Download
Killcraft-1.0.1.zipfrom the Releases page. - Unzip it into
ULTRAKILL\BepInEx\plugins\, so you end up withULTRAKILL\BepInEx\plugins\Killcraft\Killcraft.dll. - Leave
SkyCraft-Minecraft.zipin that folder, still zipped. Keepkillcraft-mc.jarthere too: Killcraft copies it into Minecraft by itself.
3. First launch
- Start ULTRAKILL. Killcraft unpacks and starts Minecraft by itself, hidden.
- The first time, Prism Launcher asks you to sign in to your Microsoft account. Minecraft and Java then download, which takes a few minutes.
- Start any level. After a moment Minecraft takes over V1.
4. Controls
Minecraft’s own controls work (WASD, Space, Shift, mouse buttons, 1–9, E inventory, Q drop). On top of those:
| Key | Does |
|---|---|
| F9 | Turn Minecraft off (plain ULTRAKILL with your guns) and back on |
| F5 | Third person: behind you, then in front, then back to first person |
| O | Minecraft’s menu (options) |
| Esc | ULTRAKILL’s pause menu. It pauses and mutes Minecraft too, or closes an open Minecraft screen |
Dying in Minecraft is dying in ULTRAKILL, and the other way round. You respawn at ULTRAKILL’s checkpoint.
5. Things to try
- The Nether: type
/give @s minecraft:obsidian 14, build a portal anywhere in a level, light it with flint and steel, and stand in it for 3 seconds. Any Nether portal brings you back to the one you came through. - Potion of ULTRAKILL: move like V1 for two minutes. Craft it from a glass bottle, sugar, a feather and redstone, take it from the creative menu’s Killcraft tab, or
/give @s killcraft:ultrakill_potion. - SMILEOS Shop block: iron ingots around a glass pane with redstone below, or
/give @s killcraft:smileos_terminal. ULTRAKILL’s real shop stands there. - Mobs on your side: spawn eggs give you zombies, skeletons, iron golems, wolves and more that go after ULTRAKILL’s enemies.
6. Settings
Killcraft makes ULTRAKILL\BepInEx\config\dev.killcraft.cfg on the first start. A few useful ones:
| Setting | Default | Does |
|---|---|---|
ToggleMinecraft |
F9 |
The key that turns Minecraft off and on |
FreshWorldEachLaunch |
true |
Fresh world and starting kit every session. false keeps your builds and inventory |
MobsAttackYouInLevels |
false |
Minecraft mobs attack you in levels too |
NetherEnemies |
6 |
ULTRAKILL enemies around you at a time in the Nether (0: none) |
BlockBrightness |
1.0 |
Lower it if blocks look too bright in dark levels |
StartWithUltrakill |
true |
Start Minecraft when ULTRAKILL starts |
The README lists the rest, including damage multipliers and Discord status.
7. Known limits
- ULTRAKILL’s weapons, movement tech and style meter aren’t used while Minecraft has the player. F9 switches back.
- Blocks don’t get the level’s baked lighting, so they can look bright in dark levels. See
BlockBrightness. - ULTRAKILL’s enemies only attack V1, never Minecraft mobs.
- Friendly mobs walk straight at enemies. They can’t path around walls or up to other floors.
- Holding right click (shield, bow, eating) stops left clicks attacking, as in Minecraft.
- Flint and steel lights ULTRAKILL floors only from the side: aim at the bottom of a wall just above the floor, or at the side of a step.
- An ender pearl thrown more than about 36 blocks comes back to you.
- Look-only effects (night vision, blindness, invisibility) don’t show in ULTRAKILL.
8. Update
Unzip the new version into ULTRAKILL\BepInEx\plugins\ over the old one.
No ULTRAKILL? Play the tribute
Start with SkyCraft, the Minecraft-in-Skyrim mod Killcraft is built on, or its browser tribute Blockrealm.