Just as tagging is really about allowing users to explicitly declare their interests, since tags are a clear and simple form of self expression, so the growing Casual Games market is really about choice and investment.
Casual games are a choice of where to invest 10 to 15 minutes of play. This might explain why game clones are so popular (with users, since a lot of them are clearly clones) since players are unwilling to try out new game mechanics when the window of opportunity is so small. A game that looks and feels like Tetris, Collapse or Bejewelled within 30 seconds of play is going to use up all of those 10 - 15 minutes of available time.
However, choice also has a lot to do with character. Casual game developers know this which is why so many downloadable and online games feature clear and strong messages of intent. The protagonist in a casual game tends to have clear objectives and little in the way of a supporting cast. You’re a bookworm, a waitress, blah blah blah.
Happily, this applies to Flash games as much as downloadable games. Perhaps more so, since Flash 5 was really a designers tool, so a lot of the current generation of flash game developers seem to have grown up with Flash and turned the desigers tool into a powerful game scripting environment. I don’t know whether this applies to the makes of Sandman, nitrome, but the lines can clearly be drawn from flash designers to flash (game) developers. Games like Gun Run are frequently to be found being developed in flash. Their hallmarks being a very focussed art and game-play brief. Just as Actionscript encourages a simple gameplay mechanic and a pared down approach to the area of focus within a game, Flash as a vector tool rewards developers who have a clear and stylised view of their games.
Which is where Sandman comes in. A puzzle game that takes around 10 to 15 minutes to play but only takes around 30 seconds to get the hang of. The theme is fantastical but not too cluttered with detail to disturb the focus of the game. It’s the character of the game that makes you want to play it again. Sandman has buckets of charm, give it 10 minutes of your time.