In the last months I spent some days on creating a little video game called RetroCosmos with the aim of submitting it to the new Calling All Innovators contest. I coded it using Qt 4.6 and made it run on Symbian. It's now available (for free) on the OVI store.
It doesn't use any fancy technology but I really tried hard to make it enjoyable to play, and I am quite satisfied with the result :)