SPIM

SPIM is a smart tool purposely designed to act as a self-contained simulator that runs MIPS32 based applications.

SPIM  is capable of reading and executing reads and executes assembly language programs put together for this type of processor. The tools can also provide an intuitive debugger and a minimal set of OS services. SPIM cannot execute compiled or binary programs.

Moreover, the whole MIPS32 assembler-extended instruction set is implemented by the app. (Note that most floating point comparisons and rounding modes and the memory system page tables are left out)

The MIPS architecture has some variants that are different in multiple ways (For example, the MIPS64 architecture fully supports 64b integers and addresses), which means that the tool won't run programs compiled for all the MIPS processors.

The MIPS compilers are also generating some assembler directives that Spim cannot process. These directives usually can be safely ignored.

Regarding the OS, on Microsoft Windows, the application offers a simple terminal UI so any user can easily find its way around it.

If you are in need of a capable app that can run MIPS32 architecture based apps, then you can give SPIM a try.