One Button Arthur
If you have played One Button Bob before, this requires no more explanation. It's the same, with just more challenges thrown in. Your single-finger-fu will be tested to the brink of your reflexes... and even if it isn't, the real goal is to complete the game in as few clicks as possible.
To the uninitiated, the 'One Button' games (as well as Nano Ninja) are broken into several screens, each with a different challenge. These may involve dodging falling rocks, avoiding flame throwers, hitting a sequence of switches, solving a slide puzzle and so on. But you only ever control the main character with a single click of your mouse. Sometimes you hold the button in to make Arthur stand still. Sometimes you hold it in to make him jump further. Sometimes it's to slash with his sword and sometimes it's simply to change direction. You'll need to experiment to figure out how to get by each unique screen, and be patient, since a single hit knocks Arthur right back to the start of the screen.
One Button Arthur is the kind of game that should take you around ten seconds to figure out. Ten seconds and a few dozen clicks in my case, but I was never a fast learner. There's not much else to say, except to note that the boss at the end is considerably less frustrating than either One Button Bob or Nano Ninja. So, let the click-score-bragging in the comments commence!
Thanks to Charlie for sending this one in!