This is cool, I can see how the simple combat could evolve into a Gauntlet style MP dungeon run. However, I think you should look into making a more creative movement scheme. WASD for 2D overhead movement is unintuitive, in my opinion. You could make it like... movement via the mouse, where the player is pulled towards the mouse, with left and right click performing quick directional sweeps with the sword. Or something.
I don't know, I just despise the trend of using WASD in Construct games. Probably because I have to change my keyboard layout to even use it.
Dual analog gamepad would be cool for this game.