FreeCell

Every card is dealt face up. Park any card in one of the four free cells, build the columns down in alternating colours, and the foundations up by suit from the ace. You can move a run of cards as long as there are enough free cells and empty columns to shuffle it through. Click or tap a card to send it somewhere useful, or drag it where you want it. On a keyboard: Tab to a card, Enter to pick it up, Enter on another pile to put it down, Escape to let go, U to undo. Games are numbered like the Windows ones, so game #1 here is game #1 there.