The RAND function returns numbers from the interval [0,1), and if you need to generate numbers from another interval, you should use the following formula: =RAND() * (bâa) + a. This will return random numbers from the interval [a,b) - greater than or equal to a, and less than b.
At the time, 5.4 was made available as a beta release alongside the stable 5.3.4 release. Now that 5.4 has become the latest stable Unity release, it seems the company intends to keep the program going a beta version of Unity 5.5 is slated to debut in the near future. source.
Quality Settings. Unity allows you to set the level of graphical quality it will attempt to render. Generally speaking, quality comes at the expense of framerate and so it may be best not to aim for the highest quality on mobile devices or older hardware since it will have a detrimental effect on gameplay.