Puppykaku

Undo and hints when you get stuck

Any move can be undone, so you can try a rectangle and back out of it without starting the board again. A hint is available for when a puzzle stalls. The listing states that each puzzle has one logical solution that can be worked out by reasoning alone.

Playing at your own pace with no timer

The listing names no timer, no lives and no time pressure, so a single puzzle fits a coffee break as easily as an hour-long grid. The developer presents it as a way to wind down or wake up the brain, and the layout suits either.

Because nothing is counted against you, you can take each grid at whatever speed suits you.

Puppies freed by solving puzzles

According to the listing, every puzzle you solve sets a pack of puppies free. That is the game's reward for finishing a grid, and it is the only reward the listing describes.