Fascinating idea with incorporating 'flash' with the typical platforming! I just wish I was a bit better at incorporating it, as I struggled to make my way across the platforms.
Just a bit of small feedback
1) I found that jump was actually bound to left-click and attack to right-click
2) It took me a while to realise how double jump work, I might suggest removing the cooldown for the mid-air jump?
3) Unfortunately my short attention span meant that I hadn't read down till the green ball resource for the flash. It seems pretty important, what about putting it up higher in the control section?