Parallel Experiment

Parallel Experiment

Released Jun 2025

Two detectives, one deadly experiment, a race against time. Each player only has one half of the puzzle. In this 2-player co-op puzzle game you can survive the parallel experiment only by working together.

85% positive · 835 reviews
Done
All announced content has been released
Medium confidence
Done
All announced content has been released
Medium confidence

Where to buy

Steam $9.99
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Evaluation

Parallel Experiment launched on June 5, 2025 as a complete cooperative puzzle game. Following release, Eleven Puzzles continued refining the game through a series of feature patches addressing bugs, accessibility improvements, and quality-of-life features (patches 1.0.6 through 1.0.7 between August and September 2025). On March 4, 2026, the developer shipped a substantial free update — Parallel Experiment 2.0 — which added a brand-new level ("Temple of Trials"), a reworked finale, an entirely new hint system with over 300 hints, updated conversations and cutscenes, cloud saves, and numerous bug fixes. The developer framed this as a response to player feedback, explicitly stating it was large enough to have been sold as paid DLC but was being released for free. This update addressed their own acknowledged shortcomings with the original release (a rushed ending, lighter second half) and was presented as delivering the complete, intended experience. Since the 2.0 release, the developer has issued two maintenance patches (2.0.3 on April 2, 2026 and a Steam Deck verification notice on April 14, 2026), neither of which announces new content. No roadmap, unshipped DLC, or future content commitments have been communicated. The developer has not indicated any further content additions are planned. The game appears to be a finished, self-contained product. The 2.0 update represents the developer's completion of their original vision for the game, and the subsequent patches are purely maintenance. There are no signals of additional content on the horizon.
Evidence
Parallel Experiment 2.0 released for free, adding a new level, reworked finale, a new hint system, cloud saves, and numerous bug fixes. Developer described it as large enough to be paid DLC but chose to release it free to address player feedback.
news post · Mar 4, 2026 source content shipped
high
Patch 1.0.7 added new control options, ability to rewatch cutscenes, and Android back button support, alongside bug fixes.
news post · Sep 26, 2025 source development ongoing
medium

Content

1 of 1 released · no outstanding content

Media

Details

Developer
Publisher
Eleven Puzzles
Achievements
26
Platform
Windows, macOS
Controller
—
Steam Deck
Verified
Players
Multiplayer · Co-op

About this game

IMPORTANT: "Parallel Experiment" is a 2-player cooperative puzzle game with escape room-like elements. Each player must have their own copy on either mobile, tablet, PC or Mac (cross-platform play is supported).

In the game players take on the roles of two detectives who are often separated, each with different clues, and must work together to solve puzzles.  Internet connection and voice communication are essential. Need a Player Two? Join our community on Discord! Find the link on the side of our Steam page.

Parallel Experiment is a noir-inspired adventure with a comic book art style, featuring detectives Ally and Old Dog. While following the trail of the dangerous Cryptic Killer, they suddenly become his targets and are now unwilling participants in his twisted experiment. 

This is the second standalone chapter in the “Cryptic Killer” cooperative point-and-click puzzle game series. You can play Unboxing the Cryptic Killer first, if you want to learn more about our detectives and their nemesis, but Parallel Experiment can be enjoyed without prior knowledge.

KEY FEATURES

🔍 Two Player Co-Op

​In Parallel Experiment, players must rely on their communication skills as they’re separated and must each discover unique clues that are vital for solving puzzles on the other end. Teamwork is essential to crack the Cryptic Killer’s codes.

🧩 Challenging Collaborative Puzzles

​There are over 80 puzzles striking the perfect balance between challenging yet fair. But you're not facing them on your own! Communicate with your partner on how to best proceed, solve a puzzle on your end that unlocks the next step for them and discover a wide variety of puzzles from redirecting water flows, finding computer passwords and unlocking intricate locks, to deciphering cryptic ciphers, soldering electronic components, and even waking up a drunk!

🕹️ Two Can Play That Game

​Looking for a break from the main investigation? Dive into a variety of retro-inspired mini-games designed with a fresh cooperative twist. Challenge each other to darts, Three in a Row, Match Three, Claw Machine, Push and Pull, and more. Think you know these classics? We’ve reinvented them for a whole new co-op experience

🗨️ Cooperative Dialogues

​Uncover vital clues through collaborative conversations. NPCs respond dynamically to each player, offering new layers of interaction that only teamwork can unravel. Some conversations are puzzles in themselves that you need to solve together!

🖼️ A story told in panels

Our love for comic books shines in Parallel Experiment. Every cutscene is presented as a beautifully crafted comic book page, immersing you in a gripping, noir-inspired narrative.

How many pages did we create to tell the story? Almost 100 pages! Even we were surprised by how much it took, but every panel was worth it to deliver a story that keeps you on edge until the very last frame.

✍️ Draw on… Everything!

​Every detective needs a notebook. In Parallel Experiment, players can jot down notes, sketch solutions, and interact with the environment in creative ways. But we all know what you're going to draw first…

🐒 Annoy Each Other

​This is a key feature? Yes. Yes, it is. ​

​Each level will have some way for players to annoy their co-op partner: knock on a window to distract them, poke them, make their screens shake. You already know you'll be doing this just by reading it, right?

Parallel Experiment has a variety of mind-twisting challenges that push the boundaries of cooperative puzzle design, offering situations never seen before in other games.

Last evaluated Jun 21, 2026
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