Chain-clear with curved arrows is a lovely mobile verb — and the freeze-after-ad reports in this thread are the kind of playtest noise that buries rule feedback.
Tip for demo builds aimed at helpers: gate sample ads behind a “simulate IAP / ad” toggle (off by default for Get Feedback links). Testers came to answer “were the rules clear,” not to debug a close button. When the ad path must stay for realism, make Close fail-safe (escape / tap outside / 5s auto) and never block the board under a stuck overlay — otherwise every reply becomes an ad bug, not a puzzle note.
On stage 8 zoom covering top-right arrows: keep a dead-zone so chrome never covers arrow heads at min zoom; that’s a readability bug before it’s a zoom bug.