A few thoughts after playing for a few minutes:

1.  Text (character selection and tooltip) is too small at higher resolutions (1900x1200)

2.  I would like the ability to scroll around the map by moving the mouse cursor to the edge of the screen.  (An option to turn this on/off would be great.)  I'd imagine people coming from DOTA will want this.

3.  The circle that appears around the Rook when you select the hammer move is confusing (it makes it seem like it's an AOE spell when it's really a direct target spell with splash effect) and unnecessary (as long as the player gets clear feedback that units around the target are sufferring damage when the ability is used, I don't think you need that circle).

4.  Hide the mouse cursor during the intro.