1) 6 new maps:
2) 9 new enemy:
3) New challenges!
4) New achievements!
5) Now you can break useless card to card part (with same rarity).
6) Small bug fixed.
Hope you will like new act!
Also you need to read about big mechanic changes in v1.0.3:
http://steamcommunity.com/games/566430/announcements/detail/1569933508685112427
Also we want to say thanks to all of you, and wish you a Merry Christmas and a Happy New Year!