Important search. Something OMB should have created decades ago. A priority item within the Open Source Agency (OSA) concept of service to Whole of Government and unscrewing the DoD acquisition process which is corrupt to the bone (front-loading, false assumptions, etcetera). Warning notice: the big money is focused on reducing the deficit as a financial play that benefits Wall Street speculation. An honest budget simulator would also include true cost economics (cradle to grave internal and externalized costs) and would strive to eradicate fraud, waste, and abuse that is roughly 50% of every federal dollar at this time. Such a game or simulator does not exist because it would be in the public interest and expose the intiimate details of what Matt Taibbi calls Griftopia.
Budget Simulator (Citizen Focus)
Committee for a Responsible Federal Budget
EconEdLink National Budget Simulation
Participatory Budgeting Practices, Games, Resources