I just won a conquest victory on challenging difficulty level.  I had a few thoughts and bug reports.

1) The plus symbol ( + ) in the UI often look like a minus symbol ( - ), because the vertical line in the plus symbol is very faint.

2) My starting champion became god-like around level 20.  I didn't need any other units to win.

3) During tactical battles, there is a list of spells and other special abilities in the lower left of the screen.  When an enemy casts fear, this UI will disappear.  When this first happened I didn't know how to end my turn, as I couldn't cast a spell or press the "pass" button, but I eventually used a keyboard hot-key to end my turn.  The missing portion of the UI was visible again on subsequent turns.

4) I was playing with auto-turn enabled.  Towards the end of the game the auto-turn stopped working.  I think there may have been something requiring my attention, like a unit with unused moves, but I never could figure out why auto-turn wasn't working.

5) Beta 5 plays and looks better then previous versions.  Thanks for the improvements.