While waiting for US release, Rise of Flight's core-game is now free.

[AndyJWest]

Bah! Only downloaded the previous demo a couple of days ago - have to do it all again...

Seriously though, this looks like a generous offer, and an interesting marketing technique - probably learned it from the dodgy-looking guy on the street corner. You know, 'have this free on me' and when you are addicted and need another fix, you have to start paying (though fortunately, not quite as much...). Definitely worth a look.