Targets pop up and you tap them before they vanish. The rules are as direct as that, and the challenge comes from keeping up as things speed along, testing your reflexes and accuracy. Free, no download, and it works in your browser, including on a phone.
Palavra Cruzada is a Portuguese crossword puzzle with 120 levels to work through. Each grid leaves blank squares and clues, and you fill in the words so the crossing letters match up. With that many levels there is plenty to chip away at over time, and the whole thing runs in the browser with no download.
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