One shared mechanic, two different games: Alan Hazelden reads Every Door a Portal against his own Fort Locks

Introduction

Today's Tsumiki roundup. One piece today. The subject is the July 2026 edition of Thinky Third Thursday, a column on the English-language, puzzle-focused outlet Thinky Games (by Alan Hazelden, published 17 July 2026), which I read in full in the original English.

I remain, as ever, someone who dreams of designing puzzles but is still bad at solving them myself. Even so, I was quietly impressed by how two games sharing the very same core mechanic split into completely different experiences over just two design choices.

'The key you used rewrites reality': Alan Hazelden on where his own game and a jam entry diverge

Thinky Third Thursday is a monthly column written by Alan Hazelden himself, founder of the puzzle studio and publisher Draknek & Friends, and published on Thinky Games. Hazelden is the designer behind A Monster's Expedition, Cosmic Express, and A Good Snowman is Hard to Build (Puzzlebyrinth previously covered his design philosophy, drawn from his own remarks, in our 'designer-hazelden' piece; related ↗). In the July edition, Hazelden highlights favorites from the Thinky Puzzle Game Jam 6, an annual jam organized by Dom Camus themed 'Locked Room' that drew over 80 submissions. Source ↗

One entry is All the Gold in Fort Locks, a game Hazelden himself came up with the concept for (made together with Lucas Le Slo, Benjamin Davis, and Murray Somerwolff). The premise: steal all the gold in Fort Locks using the magical power of opening doors.

Hazelden puts this side by side with another jam entry, Every Door a Portal by ELAiNE, and draws the comparison himself. Both games share the same core mechanic — what lies behind a door changes depending on which key opened it, overwriting reality. But, he writes, ELAiNE's game lets you conveniently keep those keys in an inventory, while his own game requires physically pushing the keys around; and ELAiNE's game spreads its puzzles across 11 standalone levels, while his is a single interconnected challenge.

Hazelden calls this 'a great example of how similar game ideas can diverge and very quickly become totally different experiences.' Why it matters: what stands out here is the designer's own account, side by side, of how just two secondary choices — how keys are carried (inventory item vs. pushable physical object), and how levels are structured (standalone vs. interconnected) — can send a single shared mechanic down completely different paths. A game jam's short timeframe and single theme make this kind of divergence unusually easy to observe.

The same edition also notes that the latest episode of the Draknek & Friends official podcast features Ausiàs Dalmau Roig (developer of Is This Seat Taken?) discussing the design of puzzles with multiple solutions — though the article itself doesn't go into the substance of that discussion, so I'll leave it there for today.

Today's Favorite Line

"A great example of how similar game ideas can diverge and very quickly become totally different experiences!"

(the line as written in the original English article, by Alan Hazelden)

Sources

Today's featured article:

・Alan Hazelden's Thinky Third Thursday — July 2026 (Alan Hazelden, Thinky Games, 17 July 2026)

Closing

Today's piece let the designer himself put into words why two games built on the same idea ended up feeling so different. Change how something is carried, change how levels connect, and the same shared mechanic becomes a different game — I'm still bad at solving puzzles myself, but I'd like to get better at spotting these divergence points on my own. Tomorrow, I'll go looking for the next design discussion somewhere else in the world.