I bought this game on a whim because my girlfriend is a King Arthur nut. My first impression of it is that King Arthur the Card Game is a fairly light game with very little player interaction.
If you are intrigued by the theme, I would advise you to play before you buy. The artwork is rather nice, but the theme is slapped on. You might be OK with this if the theme were soaked with "Arthurian Legend-ness", but, theme itself has little to do with King Arthur. I mean, there is an Excalibur card, and a Holy Grail card. Oh, and Merlin has a card too! But most of the cards seem to be generic Fantasy type stuff. There are also Dragons, Rock Monsters, Wolves, etc.
There are 3 types of cards total:
a) Colored cards (we slap knights onto those)
b) Numbered cards (we slap monsters, dragons, 'dark powers', and bad knights onto those)
c) Point cards (we slap different 'quests onto' those: 'The Fisher King', 'Battle with Vikings', etc..)
Basically, to win the game, you save up (a) cards to buy (b) cards. At the same time, you save up (b) cards to by (c) cards. There are are 13 (c) Cards. You want those. At the end of the game, you add up all of the points on these cards. Whoever has the highest score wins.
Once you get the hang of it, you can complicate it with cardboard circles.
Now, none if this is to say that the game isn't enjoyable. I don't think the game is very profound, and it might be better with a larger group. We did have fun playing it, though. The game mechanics are certainly different. I will play this when I want something that isn't very long. It might also be fun to play with my nieces and nephews.