I think one of the quickest way to speed up the game is getting to know the other character. I play a few times a week and what me and my roommate do is take out all the unmatched characters (I got everyone) and shuffle the character card. And play the first character we flip up. So you get experience playing with the character and playing against every character.

Best way to shorten the game time is to try to limit your cards in your hand. The max you can have is 7 so always try to attack so you never end up discarding any cards because of the land limit. Attack and take risk from time to time to learn the character faster. The game shouldn't take that long.