If you have five spare minutes, Brick Sprint will fill them. Everything happens on one screen with a 6×10 brick wall and a paddle tuned to 25% of the screen, and the whole thing runs straight in the browser - no downloads, no sign-ups, no fuss.
Levels clear when the last brick falls, and losing the ball costs a life; three lives, no more. The geometry does the heavy lifting - steep angles reach the back rows, shallow ones farm the front, and a well-timed sharp return can carve a tunnel through everything.
Nothing here needs a tutorial or a wiki. Controls are one gesture, the goal is one sentence, and the difficulty comes from execution rather than homework. That is exactly what a browser game should be.