i give my suggestions in 1/2/3/4 format :

1 biger screen when we play @ pc desktor using chrome browser (or better resolution and textures), maybe same HQ mode as choice for android and ios hi-end devices
2 "sell all" or selectable sell options in inventory (to speed up process, very bored to click click click click until get rid of all low lvl items)
3 more work on luck factor, pet with luck in expansion, luck items... stacked with lepre and elixir <- something in that way
4 more deeply interaction and relation between players, better chat interface, pvp mode in big open world where ppl can group, ambush others and all that funy stuff

what you ppl think?