I'm a big fan of TBS and MtG, and to see a combination of both is quite a nice surprise.
Event though the comparison with Magic the Gathering would seem straight forward, I don't consider it relevant. Yes, the basis of both games is based on playing a hand of cards, but in Guardians of Graxia (GoG) you don't have control over your deck. Which isn't bad, actually it doesn't even matter. The actual game I consider closer to Heroes of Might and Magic and Chess than a card game. In terms of card possibilities the game is much more straightforward than MtG. This makes it very appealing for new players, without loosing it's tactical appeal. With the basics nicely explained in the first scenario, all that's left is to experiment and try to master the great strategical possibilities this game offers.
The number of maps might seem small (campaign plus skirmishes give 9), but they are well thought, each of them having a high replay value.
Sounds are really well done, with the graphics having moments when you wish you'd see more detail. The up side is that the game runs without flaw on current average machines (including laptops), at maxim detail.
As for the negative parts, I'd have to mention the lack of multiplayer as the biggest. It would add tremendously to the game's life, even if the AI is able to offer quite a challenge. Regarding this, it would have been also nice to have a difficulty setting.
Another big minus is the lack of a manual and keyboard shortcuts (even if Esc is very important in the game :) ).
Gameplay wise, the interface leaves a bit to be desired. It doesn't show too much information on the current status. For example there aren't any indications on which effects are current on a given creature, or how many more points from an ability are still to be used.
In the game itself, I would have liked the option to rotate the camera, the lack of which seems a bit strange considering it's a 3D game played on a chess like board. For me, this is important, as I don't like to stare at the back of my creatures for the entire game.
One of the big cons mentioned in all reviews is the lack of a map creation tool. This I hope will be remedied in the future, since the creators have a good background in continuing the development of their games even after launch. As a final remark, it definitely needs to have a detailed description of saved games, since it displays just their name.
In spite of it's few big negatives, the game is well deserving of a good 4/5, considering the great tactical depth it provides, great gameplay and attention to detail. All of it for a price that is more than appealing.