It's bit slow, and there are some bugs, but it mostly works.
Vaporator, some bugs I noticed while playing:
MAGMA casts Bottle Gnomes, I counter it with Exclude, MAGMA sacrifices Bottle Gnomes for 3 life in response.
MAGMA attacks with a creature, (thus tapping it), and before damage goes on the stack, I return it to hand. MAGMA replays the creature during the second main phase, but it comes into play tapped, (Because it was tapped before?).
Also, the AI, even on the highest difficulty level, does stupid and pontless things sometimes, like attacking when I can obviously block and kill the attacking creature with somehting much bigger, or lightning bolting something much bigger than 3 without following it up with anything. If it's got some sort of learning mechanism, then cool, but right now it's not any harder to outwit than the old Microprose game.
EDIT: I realized I owed you more than this. So here's more comments.
1) I really like this project. It's ultimate value is that you can build whatever kind of deck you want, and then play it against an always-available opponent. So keep up the good work.
2) To those thinking about playing it, but don't like the current card count, don't worry, it's got an intersting enough cross-section of spells that you can build most styles of decks. Yes, it's limiting, but there will be more to come and enough fun stuff is there right now to make it worth playing.
3) The biggest problem I have with it so far, actually, is not the occasional rules glitch or wave of stupity, but the pacing of the game. It moves too slow to convince me to sit down and play more than a few games at a time. I don't mind having to right click through every moment of priority, in fact I think that's an elegant way to access the comlexity of the game, it's just that animation and sound and such really takes up some time. I would prefer more basic graphics and no sound if it meant the game would could move as fast as a real game.