Applying Light Source Effect

[iron59]

Good day. I'm making a game wherein a character has a light source which determines the player's view in a circular shape, much like a lantern. To do this, my approach would be to create a new object with tk2D sprite with transparent circle on the center, but I want its transparency to gradually decrease as it goes farther from the circle's center. Is there any way to do this in tk2D? Thank you very much.

P.S. - I'm open to other suggestions to simulate the light source mechanic. Thanks again. 

[unikronsoftware]

You could just use a real unity omni light with lit shaders, that should work just fine with one light source.