Puzzle Quest: Galactrix Preview

IGN has posted a pretty good overview of Puzzle Quest: Galactrix, comparing and contrasting it to its Challenge of the Warlords predecessor.
In Puzzle Quest there was a slew of characters and classes to choose from, but Galactrix offers only two -- a male and a female. There doesn't seem to be any difference between the two, other than cosmetic.

The game world in Galactrix is much, much bigger. It can be a bit daunting the first time you gaze at the galaxy map, with dozens and dozens of systems each containing missions, shops, its own economy and government, and mini-games.

In order to gain access to new areas of the galaxy map you have to complete mini-games. Basically, you have to hack a leap gate by matching gems in a specific order within a time limit. Hacking challenges increase in difficulty as you progress.

Like Puzzle Quest, you can add members to your party in Galactrix. But instead of giving you a small boost in battle, they unlock complete game features. Adding the character Lydia to your party, for example, will allow you to mine asteroids for valuable cargo, which can be sold around the galaxy.

In Puzzle Quest you could lay siege to any castle you visited, take control of it, and add it to your empire. From then on it would pay taxes to you whenever you passed through. Sadly, this feature appears to be missing from Galactrix.
I'm not too keen on the lack of classes. Hopefully that just means that each character has more skills and abilities to allocate points to.