As a hujungnormous fan of classic gaming. I like the bare bones aspect of classic games where concept goes farther than graphics. Classic gaming can still be a lot of fun if I get past the graphics and try becoming involved with the game. I’ve been lucky to stumble upon a couple ones lately. One is awesome, another is still in development.
Cave Story is about a robot ( Quote ) that magically ends up in a cave where Mimiga live (mean but adorable(?) bunny type creatures). I’m not gonna ruin the plot by giving a whole synopsis but the story is imaginative, detailed and interesting. Cave Story is a classic 2d platform game like a Mario Bros. or Contra. It has a lot of characters and deliciously diabolical evil bosses. The author spent 5 years on an off creating this and it feels well-polished. Wikipedia as a good entry on it.
Not too long ago the author release a Linux binary for x86, so for the free-software enthusiasts this may not be kosher, otherwise I like this game a lot. A fair challenge even for an adult. Check out the game tome for more.