Free
In-App Purchases
Rating summary
About
Venture into the unknown. Uncover the logic behind every puzzle.
• 50 individually designed puzzles
• Four difficulty collections with a steep rise in complexity
• Logic, spatial, visual, word, mathematical, and discovery-based challenges
• Little to no instructions
• No ads or time limits
• Playable offline
The first three collections contain 30 puzzles, ranging from approachable experiments to demanding multi-step challenges.
An optional in-app expansion pack unlocks the "Very Hard" collection consisting of 20 puzzles created for experienced solvers. This is not simply another step up. Its deepest challenges may take hours, days, or even longer to unravel.
Look closely. Test your assumptions. Find the rule that was there all along.
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What's New in Index Unknown
1.0.2
August 27, 2026
Improved controls in various places.
1
Subscriptions & In-App Purchases
$4.99
Expansion Pack - Very Hard
Unlocks the "Very Hard" section.









