Defenders of Avalon is a bullet-hell shmup that is not so completely impossible to make it frustrating. Set in a medieval background, you play either Arthur or Merlin which is just a clever way to give you alternate shot types. No story, no reason for there to be one, fun to play.
Approaching Dawn, a purely platforming old schooler with some retro charm. The game essentially consists of timed rooms full of hazards but the only one you are competing with is yourself. It comes in a Lo-Fi and Hi-Fi version, but the differences are minimal.
Finally we have eXtermination is another Zombie-fest side-scroller, but an enjoyable one. Game play consists of platforming with mouse targeting and controls well. One problem on the site at the moment is the download link is broken, you can grab a slightly older version by changing the URL slightly