Parallel Experiment Two Detectives, One Killer's Puzzles

You and a friend play Ally and Old Dog, two detectives hunting the Cryptic Killer who end up as targets in his experiment instead. The catch: you are often separated, and each of you finds clues the other one needs. Your half of a cipher is useless without their half of the key.

So you talk. Constantly. One of you describes a symbol while the other scrolls through notes, and somewhere between the two descriptions the answer clicks. It is a puzzle game built on voice chat, where the real mechanic is how well the two of you explain things to each other.

The puzzle list runs long and wide: redirect water flows, dig up computer passwords, crack intricate locks, decipher ciphers, solder electronics, and wake up a drunk (yes, that is a puzzle).

The range keeps things fresh. Just when you think you have the format figured out, a new kind of challenge shows up. Some of the co-op twists here, like hiding not just clues but the context of a puzzle on the other player's screen, are the kind of thing you will not have seen elsewhere.

Every cutscene is a hand-drawn comic page, noir style, and there are almost a hundred of them. The tale of Ally, Old Dog and the Cryptic Killer unfolds frame by frame, with a story that takes twists neither of you will likely call in advance.

Fair warning: this chapter leans harder into its story than the earlier games in the series, so expect more talking and more panels between puzzles. If you are here mostly for the mystery itself, that is part of the deal, and the panels are good-looking company along the way.

This is a proper case to work, not just a string of locked rooms. You follow the trail of a serial killer, question characters, and piece together what the Cryptic Killer is actually up to. The point-and-click structure means you roam locations with several rooms, poking at everything while your partner watches your every move.

Conversations are part of the investigation too. Both of you talk to the same characters, each with your own dialogue options, and some chats are puzzles in themselves that only make sense when you solve them together. The trail gets stranger as it goes, and the answers are worth the work.

Everything here assumes a partner. An internet connection and voice chat are essential, because the game is essentially one long conversation with puzzles in it.

When the case needs a breather, challenge each other to co-op versions of darts, Three in a Row, Match Three, a claw machine and Push and Pull. The classics are reinvented so both players share the controls, which is exactly as chaotic as it sounds.

Most co-op games scale to four and leave someone quiet. This one is built for a duo, and it shows: every puzzle has two halves, every conversation has two voices, and the whole campaign runs on the back-and-forth between you. Around eight to twelve hours together, depending on how stubborn you both get.

There is also a formal system for settling scores: each level hides a way to annoy your partner. Knock on their window, poke them, shake their screen.