Mewgenics 100% Quest Completing: Advanced Guide

This guide details the path to fully completing Mewgenics, covering every quest required for 100% completion. Learning how to complete Mewgenics for 100% involves understanding the two main quest types: Invention Quests, which offer unique items, and Progression Quests, which unlock new areas and advance the main story. This walkthrough covers the requirements for unlocking all acts, the solutions for every multi-step quest, and the strategies needed to overcome the game’s toughest challenges. It provides a comprehensive roadmap for navigating the world, from the initial alleys to the secret endgame zones.

Mewgenics Walkthrough: Acts & Areas

The main story progression in Mewgenics takes you through three acts, each containing multiple zones and challenges. To advance, you must complete runs in designated areas, which unlocks the next stage, as detailed in our Mewgenics All Acts guide. Some zones are hidden and require the completion of specific, multi-step quests tied to the game’s lore and bosses.

Success depends on strategic team building and careful preparation. A balanced team is essential for long runs; a Cleric's healing is invaluable. Improving your home base with furniture enhances house stats, which affects the quality of cats available for breeding, a fundamental component for tackling the game's later stages.

Invention Quests vs Progression Quests

In Mewgenics, quests are divided into two categories that concern special items a cat must carry to a specific location, often making runs more difficult due to unique modifiers. Invention Quests become available from Dr. Beanies after you send him five cats with mutations, birth defects, disorders, or parasites. Completing the quest turns the item into a regular piece of gear without the difficult modifier and rewards you with 200 coins. Progression Quests involve items dropped by house bosses, and you undertake these activities in succession. The destination for these items is always fixed, and if you fail, you can speak with Dr. Beanies to receive the quest item again.

All Mewgenics Invention Quests

The following invention-type quests are offered by Dr. Beanies and the required destination for these items tends to be randomized upon each new attempt. Completing these tasks successfully also unlocks their corresponding achievement in the game. These items add significant challenges to a run through their powerful and often disruptive modifiers.

• Persuasion Device — Modifier: Lose -2 SPD. Use to permanently Charm a non-boss enemy, causing it to join your party.
• Bubble Boy — Modifier: All units rebound with Knockback 5 upon contact. Reward: Bubbles, an item that throws a bubble with Wind and Water elements, inflicting Confusion.
• Angry Face — Modifier: The cat equipping this item becomes an enemy and must be downed to win the battle. It is cursed and cannot be unequipped or worn by a Collarless cat. Reward: Happy Face, which lets the cat spawn near enemies and take an AI-controlled bonus turn at the start of battle.
• Experimental Treatment — Modifier: Your team’s passive ability level-ups offer disorders instead. Reward: Disorder Decoder, which reduces your spell mana cost by -1 for each disorder you have.
• The Loner — Modifier: Kills all of your allies at the start of each battle. Reward: The Loner Mark 2, which deals 5 damage to anything in your line of sight. It reloads when any ally dies.
• Chaos Device — Modifier: When any cat levels up, they are offered abilities from all classes. Reward: Chaos Controller, which offers abilities from all classes on level up and allows three rerolls.
• Redacted — Modifier: Health bars and status icons are hidden in battle. Reward: Paper Bag, which sets your CHA stat equal to your highest stat.
• Storage Locker — Modifier: Your team's active ability level-ups offer rare items instead. Reward: Armory Key, which lets you find an extra item after each battle.
• Me Stone — Modifier: The cat holding this item always levels up, even if downed, while other cats do not. Reward: Suck Stone, which drains up to 5 mana from each ally at the end of your turn.
• Magic Mirror (Broken) — Modifier: Your team has very bad luck during events, and you gain +2 Thorns. This item is cursed and cannot be unequipped. Reward: Magic Mirror (Fixed), which gives a +20% chance to reflect projectiles and spawns a friendly Spookie when downed.
• Unidentified Pills — Modifier: Gain +8 Shield, but the entire adventure becomes harder with tougher enemies. Reward: Truck Stop Pills, which grant +3 Brace and make you count as a rock.
• Ultravision 3000 — Modifier: Events are harder, and all normal events trigger two extra events. Reward: Ultravision 3000 v1.1, which grants +4 LCK and makes your basic attack inflict Marked. This item is cursed and cannot be unequipped.
• Glass Cannon — Modifier: Fills the map with glass at the start of each battle. Reward: An item that shoots a glass ball anywhere.
• Mysterious Dice — Modifier: Your team's level-up options are complete chaos. Reward: The D6, which permanently upgrades one of your abilities at random with a single use.
• Party Detonator — Modifier: All units explode when they die. The item can be used once per battle to explode a random unit. Reward: Party Detonator (Fixed), which explodes a random unit within a target radius once per battle.
• Nuclear Knife — Modifier: A melee attack whose damage equals its charge count. It gains +1 charge at the end of each turn, explodes if charges exceed 10, and loses half its charges on a kill. Reward: Nuclear Gun, which deals 40 damage to a target and 20 to everything else, with a 20% chance to break on use.
• Spider Injector — Modifier: Applies Infested 4 to all allies at the start of each battle. Reward: Spider Baby, which applies Infested 1 to all enemies at the start of each battle.
• Princess Hat — Modifier: You gain +10 Shield but can only use the Move action. The item is fragile and breaks if you're downed. Reward: Used Princess Hat, which grants +6 Shield.
• Stopwatch — Modifier: You have five seconds to make decisions in battle before cats act randomly. Reward: Stopwatch (Fixed), which lets you or a target unit take an AI-controlled bonus turn.
• Fart Face — Modifier: Applies Poison 1 to everything at the start of each battle. Reward: Robo Fart Face, which applies Poison 1 to all enemies at the start of each battle.
• Air Horn — Modifier: You are ambushed in every battle. Use it to make noise. Reward: Amplified Air Horn, which applies Madness to a unit within 5 tiles in your line of sight once per battle.

These quests originate from Dr. Beanies' inventions and present unique challenges. The subsequent sections will detail the progression quests, which are tied to the main story and unlocked by defeating house bosses. These quests contain major spoilers for the game's plot.

The Mewgenics classes dictate a cat's starting statistics, initial abilities, and their specific role within a party. You begin the game with access to several foundational roles, but you unlock a total of fourteen distinct classes by defeating bosses in new areas and then speaking to a character named Butch. This progression system gradually introduces more specialized roles, from the healing-focused Cleric to the unpredictable, high-variance Jester.

All Mewgenics Progression Quests

Progression quests are tied directly to the main storyline and are essential for unlocking new acts and the game's secret areas. These quests are initiated by defeating the major house bosses encountered at the end of specific zones. Each quest involves carrying a special item with a powerful, run-altering modifier to a predetermined destination.

Act 1 Progression Quests

The first set of progression quests revolves around the house boss Guillotina, who is encountered three times. These quests introduce instant-death mechanics, placing a heavy emphasis on survival. Completing these quests is the key to unlocking the game's first secret area, the Throbbing Domain. Each item dropped by Guillotina must be taken to a specific landmark within the zones of Act 1.

• Throbbing Gristle — Destination: Wall of Flesh in the Caves. Modifier: All units, including enemies, die instantly when downed. It can be used as a melee attack that turns victims into meat.
• Putrid Leech — Destination: Throbbing Artery in the Boneyard. Modifier: The bearer never levels up and dies instantly when downed. It grants lifesteal on all attacks and is a cursed parasite.
• Guillotina's Head — Destination: Meat Altar in the Throbbing Domain. Modifier: All battles are hard battles, enemies prioritize attacking you, and units that attack you may be Feared. This item is cursed.

Survival is the main objective, as the "corpse health" mechanic is removed while these items are active. For the Throbbing Gristle, this applies to all units, while the Putrid Leech only affects the cat carrying it. After bringing the first two items to their respective locations in separate runs, the Throbbing Domain becomes accessible. To fully unlock the area, the cat carrying Guillotina's Head must be sacrificed at the Meat Altar, a permanent choice that removes a teammate for the remainder of that run.

Act 2 Progression Quests

After completing the first act, the progression quests in Act 2 are initiated by defeating the house bosses Pyrophina and Zaratana. These quests unlock the second secret area, The Rift, and require clever manipulation of item mechanics and boss encounters. The items obtained from these bosses have unique properties that must be used in specific ways to advance. One quest involves a "hot potato" mechanic, while another requires powering up an item across multiple runs.

• Scalding Orb — Destination: Man in the Moon. Modifier: Grants +3 SPD but applies Burn 3 each turn unless tossed to an ally with an open weapon slot.
• Black Shard — Destination: N/A. Modifier: Absorbs units with X or less health to increase its power, which is saved across runs. After 20 absorptions, it transforms.
• Glowing Black Shard — Destination: The Coven. Modifier: Deals 5 damage with Lifesteal and Burn 5, purges all debuffs, and can be used to instantly kill the Coven boss.
• Pyrophina's Collar/ Zaratana's Collar — Destination: Moon for Pyrophina, Core for Zaratana. Modifier: The corresponding boss joins your party as a massive, powerful, but uncontrollable ally.

To complete the Scalding Orb quest, you must carry it to the Man in the Moon boss and have the character holding it be eaten, which instantly kills the boss. The Black Shard must be powered up by absorbing 20 enemies across multiple runs until it transforms into the Glowing Black Shard, which is then used to instantly defeat the Coven boss in the Core. After these two steps, a special encounter occurs where you fight both Pyrophina and Zaratana; the collar of the surviving boss allows them to join your party, and you must take them to their respective obelisk to finally open The Rift.

Act 3 Progression Quests

The final act's progression quests begin after you clear the Labs for the first time and discover a broken time machine. These quests involve time travel, repairing future technology with artifacts from the past, and facing robotic doppelgangers of previous bosses. The challenges introduced are some of the most complex in the game, requiring careful management of chaotic modifiers and endurance through grueling runs to reach the game's final secret zone, The Infinite.

• Cryogenic Time Chamber — Destination: Throbbing Domain. Modifier: All non-boss enemy corpses revive with +30% HP at the end of each round.
• Receiver Antenna — Destination: Jurassic. Modifier: Grants +8 Shield, and all event nodes trigger special, random happenings in encounters.
• Transmitter Antenna — Destination: The End. Modifier: Your spells cost -2 mana, but casting a spell scrambles that ability into a random one for the rest of the battle.
• Signal Amplifier — Destination: The Rift. Modifier: Spawns a random robot miniboss with Madness at the end of the first round in every battle.

After finding the time machine, Dr. Beanies gives you the Cryogenic Time Chamber. You must take this item to the Act 1 secret zone, defeat the Throbbing King, and use the chamber to contain his heart. This repair allows travel to the Past (Ice Age, Jurassic) and Future (Das Future, The End) branches of Act 3.

Clearing these new zones causes the Cat Terminator bosses to appear. Defeating them yields the antenna quests. The Receiver Antenna must be placed on the volcano in the Jurassic zone, navigating runs where events cause random, chaotic effects in battles. The Transmitter Antenna must be taken to The End, forcing you to manage battles where your spells become unpredictable after a single use.

• After completing the antenna quests and defeating the third house boss of Act 3, Dr. Beanies provides the Signal Amplifier.
• This final quest item must be carried through a full run to the Act 2 secret area, The Rift.

The item's modifier spawns a random robotic miniboss in every single battle, including other boss fights. After defeating Chaos within the Rift, you insert the amplifier into the floating head, which unlocks the game's third and final secret zone: The Infinite.

How Many Hours Do You Need To Beat Mewgenics For 100%?

According to game creator Edmund McMillen, the time investment for Mewgenics is substantial. In an AMA on Reddit, McMillen estimated that it would take an "average player about 200+ hours to 'beat the game' and 500+ hours to 100%." PC Gamer noted that even reaching what appears to be the end of the main questline could take over 100 hours, suggesting that McMillen's definition of "beating the game" may include replaying levels on harder difficulties.

Data aggregated by HowLongToBeat offers a different perspective based on player-submitted times. According to its polling, the main story takes approximately 57 hours to complete. For players who engage with the main story plus extra content, the time extends to 90 hours, while a completionist run, aiming for 100%, is listed at 130 hours. Together, it's ~392 hours of gameplay.

The time to 100% the game will vary significantly based on player skill and what one considers full completion. While player data suggests a 130-hour journey, the creator's estimate of over 500 hours hints at deeply hidden secrets, such as finding ultra-rare cryptid cats, that extend the experience far beyond standard achievements.