This definitely has potential!
First of all, congratulations on this game, the art is amazing! I get the feeling you guys got a lot of inspiration from rpg games and this one definitely has potential :)
Here are my thoughts (mind you i've only played for like 15 minutes so i might've overlooked some things):
Controlls:
I get the whole mouse controlled hero idea, and it does the job, though I feel it would do the game justice to have the hero follow the mouse position constantly when pressed down, instead of walking to a new position when clicked. Reasons for this are, it would require less clicking (makes it easier to controll) and makes the hero's movement also feel more dynamic.
Tutorial/feedback:
I've looked for quite some time and there is little to no feedback as of yet. (or it's very hard to find :) ) For instance, while hovering over abilities, it would help to have a small textarea that explains what the ability does. Also don't underestimate a good tutorial level :)
This last bit might be personal though: I'd have the buttons in the shop show a little more contrast between mouseover/mouseout. I can hardly tell the difference between the two.
I'm looking forward to the next installment :)
keep it up
M.