Thanks for all of your interest
We've left the rules vague to encourage as many submissions as possible. While java games that are webstartable can be submitted for review, the end product (should the game in the contest) would need to be an applet in order to be integrated with Game Trust's Game Frame API. Honestly, you can submit any java game - besides, it's free ;-)
For your information, Game Frame is Game Trust's community and commerce platform that we license to top gaming sites worldwide, like MiniClip.com and Shockwave.com. By integrating their Java web games with our API, developers get access to community features (chat, invitations, high score, ratings, profiles, etc.), increased distribution across our network, and new revenue streams (cash tournaments, subscriptions, downloads). We have full documentation and an assistant to help you through the integration process.
Feel free to contact me directly with any specific questions :-) (jonathan-at-gametrust-dot-com)