One of the best ways to test your reflexes is by playing Magic Piano Tiles, a clever puzzle game. If you want the music to keep playing smoothly with each note, you'll need to strike all the tiles before they disappear from the screen.
The object of this brick-and-mortar online game is to play the piano for as long as you can while composing and playing soothing music. Of course, the fact that this is a vertically-moving piano adds another layer of complexity. Keep your cool and play a series of descending piano chords. You'll be able to unlock doors at a dizzying rate. Do not let them fall off the screen without clicking on them first. Remember that missing also counts as a loss, so be careful.