QUERYcleaning up the puzzle gallery the skull achievement

The Skull Achievement: Which Modes Count?

DIRECT ANSWER

The Skull requires 100 solved puzzles. In a developer reply, custom modes do not count because max skills and lower piece counts could make the condition easy to exploit. A player in the same thread reports that challenge modes count; that part is community evidence, not an official rule table.

Condition
Solve 100 puzzles
Custom modes
Developer says no
Challenge modes
Player-reported yes
E1 + E2 COMMUNITYstatus checked 2026-08-09Checked 2026-08-09 CST

ELIGIBILITY REGISTER / 25

Separate source authority from player observation

The condition is official; the thread contains both a developer rule and an E2 follow-up.

Separate source authority from player observation
ModeEvidence status
Base galleryPrimary route implied by official condition
Custom modesDeveloper says they do not count
Challenge modesCommunity-reported to count

E2 source: Developer answer and player follow-up: Skull

Why this page exists: A player wants to know which modes count toward the 100-puzzle achievement.

The official condition

Steam exposes the achievement as solving 100 puzzles. It does not publish a mode-by-mode eligibility table on the achievement page.

Custom modes are excluded in the developer reply

The developer explains that custom setups can combine maximum skills and low piece counts, so those modes do not count. That direct developer statement is stronger than an anonymous guess, though it can still become version-sensitive.

Challenge counting is community evidence

A player in the same thread reports that challenge puzzles—including The Big White—counted. This site has not reproduced that result and labels it E2 rather than turning it into an official promise.

SOURCE LEDGER / PUZZLE COUNT

Follow every claim to its evidence.

E1 is first-party. E2 is a community observation or route. Later official updates can supersede version-sensitive details.

Publication limit: Custom exclusion comes from the developer; challenge eligibility is a player report and was not independently tested.