Mewgenics Patch Notes: Latest Update and Full Version History

TL;DR

• Live version: 1.1.21039, pushed to the main branch on May 23, 2026.
• 1.1 is the only balance patch since launch. It reworked breeding and the house, retuned 11 of the 14 collars, and added a new status effect.
• The two patches before it, 1.0.20870 and 1.0.20941, were bugfix and stability work. Neither moved a collar ranking.
• The 1.0 line stays available through Steam beta branches for players who want the pre-1.1 breeding economy.

Current version: 1.1.21039

Version 1.1 is the patch that changed how Mewgenics is played. The full 1.1 notes cover every line, and three things in it reach every run.

The Mutation stat stopped rerolling. Before 1.1, the standard late-game loop was to inbreed hard for stat concentration, then spend Mutation to reroll the resulting birth defects away. That cleanup step is gone. Mutation now rolls only simple +2/-1 mutations until it passes 10, and effect-bearing mutations become reachable above that. Effect mutations are not weaker; they are further away. Our mutations guide works through the new thresholds.

Inbreeding got teeth. Stimulation now lowers a parent's chance of passing on a birth defect instead of raising it, but its benefit shrinks as a kitten's inbreeding rises, and inbred kittens inherit defects at a much higher rate. The old pattern punishes you twice now. Multiple breeding rooms with a stray rotation, plus heavier Appeal investment to recruit better strays, is where the community landed.

Voice inheritance fell from 98% to 75%. A dominant voice no longer carries across a whole bloodline by default.

tool:breeding-sim

On the collar side, item:mage took the largest buff pass (basic attack and six spells gained 2 range, item:mage-blizzard reworked into a guaranteed Freeze nuke, item:mage-ice-paws now damages frozen units). item:tinkerer took the largest rework, with Throw Weapon costing no action, five abilities dropping 2 mana each, and the new Blast Resistance status arriving on its item:tinkerer-emp, Mr. Mega, Napalm, and Demo Man passives. item:hunter absorbed the largest nerf pass: item:hunter-ball-of-spiders and Flea Shot lost DEX scaling outright, item:hunter-heavy-shot lost 2 damage and picked up a 50% miss chance, and Hunter's Boon dropped to once per turn. That nerf is what moved Hunter off S and onto A on our class tier list, and it is the reason a DEX-stacked Hunter plan built before May 23 needs rewriting around LCK and accuracy instead.

Bosses were retuned alongside it. The Coven and Tormentor gained 50 HP each, Dreadnoughtus's head gained 50, Spewer dropped to 100, and Stacy rose to 125 base. Random rolls at 0% and 100% no longer advance the RNG, which tightens seed determinism for anyone routing runs off a known seed.

Patch history

Every version above spent time on the Steam beta branch first. Beta builds carry changes for community testing ahead of the main push, so 1.1 was public from build 1.1.21025 on April 29, more than three weeks before it hit main.

1.0.20941, April 1, 2026

A system-level fix to how Status Immunity initialized. Immunity effects now purge their statuses on application, closing an ordering fault where a poison-immunity item could fail to stop poison a disorder had already applied. Items like the item:tinfoil-hat now deliver their protection every time instead of depending on resolution order, a quiet buff to defensive packages in disorder-heavy runs.

The rest cleaned up the item pool. item:empty-sack, Scrap Bag, and Lucky Coin had a rarity misspelling keeping them out of their pools, and five more items were undroppable outright. item:bloody-soul-claw was healing the target it attacked instead of its wielder, so sustain plans built on it had been feeding the enemy. item:hexagram-sigil's Buff Immunity gained an exception for Magic Damage Up, restoring the magic-scaling line the item was switching off.

1.0.20870, March 18, 2026

The first main-branch patch after launch. Nothing here touched collar balance; the value was that runs which used to die to a crash now finished. Arthur lost item:tinkerer-split-the-atom, We Are One, Become Entropy, and the other item:metronome variants. Itch, item:butcher-lighten-the-load, and Chonkwalk switched from HP Loss to physical damage, the one change with real build reach: self-harm synergies keyed to physical damage had been sitting dark, and item:butcher packages built on them started working the way their tooltips described. item:space-helmet dropped from blocking 100% to 30%, taking a crutch from frontline setups that treated it as a free wall.

1.0, February 10, 2026

Launch shipped the complete game at full price with no early access window: 14 collars, roughly 75 abilities each, 900-plus items, 200-plus enemies and bosses, 707 mutations, 53 birth defects, and the full seven-stat genetics system. Steam reviews opened Overwhelmingly Positive and have stayed there.

What to check after each patch

Two things decide whether a patch invalidates your plan. Ability numbers move collar rankings, which is a tier list problem and visible within a day of the notes. Breeding and house math moves everything downstream of Gen 1, and a bloodline bred against the old rules cannot be respecced.

By that measure 1.1 is the only patch since launch that cost anyone real time. Bloodlines started after May 23 run on current rules; anything older was bred against a Mutation stat that no longer does what it did. Our breeding guide is written against the post-1.1 rules.