How ads work in Pixel Links
Pixel Links is free, and it shows ads. You should not have to guess how that works, so here it is in full: where an ad can appear, the most often a between-level ad can show up, and how to switch those off for good.
One place, and only one
An ad you did not ask for can appear in exactly one spot: after a level's clear animation has finished, before the next level loads. Never while you are drawing, never when a level starts, never as a banner on the board, and nothing when the game opens.
None of these ever brings one on: an undo, a restart, a mistake, a pause, quitting a level, coming back to the app, a hint or a skip — though if a hint draws a level's last line, that clear counts like any other. And it is never after every level.
The most often a between-level ad can appear
At least 3 levels between two ads — and, while the game stays open, at least 2 minutes
While the game stays open: no more than 3 ads in any 10 minutes, and no more than 5 in all
A brand-new player sees none during their first 5 levels and first 2 minutes of play
These are hard limits written into the game itself. We can tune our settings from a server without an update, but never past these limits: a setting that asks for more ads than this is held at the limit by the game.
Ads you choose
Two helpers can be paid for by watching an ad, and both are entirely your call. A Full Hint draws one correct pair. In Endless, a Skip moves you on to the next board, and it counts toward your run. Each button says it costs an ad before you tap it. If no ad is ready, you never wait on a black screen: the offer is simply not shown, or tells you that no ad is ready right now. And once an ad you chose has given you its reward, the game holds back its own between-level ads for a while.
The first hint on every level is free, and a hint never solves the whole level.
Switching them off
Remove Ads is one purchase, in Settings. It removes every between-level ad, permanently. On a new phone or after a reinstall, signed into the same Google account, Restore Purchase brings it back. The game never pops up to sell it to you; it waits in Settings until you go looking.
Every ad the game requests is limited to content rated for everyone, the same rating as the game.
Play time must clearly beat ad time. That rule came before the first line of ad code.