Something's misconfigured in your webserver; I grabbed the two COD files and the JAD, edited the JAD to remove the jar size line and set the jar url to 'unkown', then hosted on one of my free servers - downloads and installs 100% (and runs). It might be your .htaccess rules that are wrong.
Working URL (put in BB browser): http://rivviepop.php0h.com/bb/jt/JounceTrial.jad
My .htaccess rules for mobile content you can steal: http://rivviepop.php0h.com/bb/.htaccess
As for the game, it installs and runs on the 8100 fine -- at work so can't spend time playing (yet), but two things on this device:
- fresh install the main menu has "continue" as if I'd been playing already, doesn't make sense. Should be New Game, right?
- clicking the Pearl moves the ship (cool). However, clicking the Menu button brings up only one item, Close -- which quits the entire app. I would think there should be a 'Main Menu' option that does what the Escape key does, imho.
(the use of the escape key versus/and menu key seem to be really undefined, some apps do one thing and other's a different. no real standardization here across all 3rd party apps)