Re: Help Needed for automation tool for Flash Game
QTP does have a Flex plugin. However it does not come standard with the trial version. I'm still jumping through hoops talking to the sales guy in trying to get a trial with the flex support. I don't think it'll add any more capability over TestComplete, but it may have a better time at object recognition since in theory it should have access to the Adobe Automation API properties.
Some open source things you can consider is FlexSelenium (will require you to code, no record and playback). There's Flex Monkey, which does record and playback, but generates ActionScript FlexUnit code, so it can only run under AdobeAir. (so you'll be limited to just the boundries of the flex application)
I have not tried Ranorex or Riatest. Cannot comment on those.