When fighting battles that you cannot win. Rather than wasting 1-2 minutes fighting something you cannot win. Give an exit out.

Perhaps auto start the game with players hidden.. Then you can click to view other players instead of the other way around.

Maybe offer a lower graphics mode that would help with bogging down the server or peoples computers.

Allow us to choose which enemy on the opponent's side to attack rather than random. More interaction in the battles.

In the arena show players within 10% power of you. Rather than just the top players. More fun to battle knowing you have a chance to win.

Fix rune glitches.

Offer gifting to people in the same guild.