In section: 6.2 Nonfunctional Requirements - Perhaps replacing "; achieved by modularized code" with a new sentence mentioning use of modular programming.
For example: "All or parts of the software shall be reusable. This will be achieved by use of modular programming software design techniques.
\item[5.] Reusability:All or parts of the software shall be reusable; achieved by modularized code.
Hello, @oluowoj
Some formatting and spelling mistakes:
GamePhysicsSRS.pdf