So I've just been in a game which started about 18 Minutes before a server restart. Enough to play, right? Well it would've been if my opponent would not have stopped to play when he was down to 1 character with a single card: a parry vs my 2 characters on the victory points and only 1 point left for me to win. He'd just not click pass until the server restarted. I think that's very unsportsmanlike and I don't really see the reason for it. He was not even very good in rating or anything. It's not like he'd lose a lot... Is there any place you can go and report him yet?
So is playing really slowly. Doesn't mean it's cheating. No rules are being broken. The time limit is offered, the time limit is used.
I suggest a card-play limit of 1 minute, this means you have 1 minute to perform an action, when 1 minute has passed game will auto-end your turn for you. I put those that exploit the 20 minute time limit thing in the same category as cheaters.
Actually it doesn't really matter if it's cheating or not. I think we can all agree on that it's annoying and should be prevented somehow. The card playing limit would help I guess...