Added / Changed :

- Power fluctuation and power bonus are increase twice faster with level up ( 1 every 5 level )
- Update game engine and use a "3D" function to write some texts
- Particles generate from mouse now go into the center and disappear there
- Gold bonus is more visible and can spawn further away from the center
- Mouse is moved at the center of the screen the clicks per second >= 1 when click quit or reset.