Thank you! Yeah I had this "move bug"too a few times. But only in the HTMl version.. :/
You get some mana if you kill enemys and collect the soul energy. It can give you 1-4 Mana points back.
But the point of the game is that you are struggle at the beginning but over the time you can power up your tools.
On way for example is:
> Upgrade the soul energy droprate to gain even more of it
> Upgrade MP Reg time to get more MP over the Time
> If you level MP Reg enough you will unlock MP max - If you level this parameter up you get maximum around 250 mana.
> Another variant is to level up the damage of your skills so you kill enemys with less spells :)