random things like Snake

How to do like in Snake game that
Appear things in the room like healing or Gold, randomly,
after taking one, another appears somewhere else in the room,
and with the option to change how often they appear?

 

is it a 2D game or 3D?

if it's 2D you can use instatiate:

transform gold;
gold = Instantiate(gold,vector2(random.range(0,10),random.range(0,10)) , quaternion(0,0)) as Transform;

and then when you take it you change it's position:

gold.position = new vector2(random.range(0,10),random.range(0,10));

 

You would probably need to take into account grid size so your vector position would be a multiple of the gridsize. That is if you want to recreate the nokia snake experience.