The last ten years the military has seen large success in the use of games and game technologies within the tactical training community. First person shooters dominate this area with significant investment around the world, primarily increasing the realism and fidelity to meet perceived training requirements. Unfortunately, not all training objectives can be easily met through the current military approach to gaming. In an effort to meet these needs some organizations are investing in completely new high end game based training systems or worse, attempting to shoehorn in functionality that is not a good fit for current systems. Both strategies are leading to greater cost, system complexity, and user confusion. One methodology that has been applied to entertainment games is minimalist game design. Minimalist games designs generally define small games with compact but rich rule sets that provide narrow decision spaces and often abstract world representations without diminishing the perceived depth of play. These minimalist designs create micro worlds in which a player can experience and experiment with a distinct subset of rules to train on requirements that would not necessitate a large simulation game. Further, they meet the promise of replay ability, self-regulation, and motivation that other gaming solutions often lack. This paper looks at how minimalist game design can be leveraged in serious games in order to focus on delivering a particular learning or training outcome. Using case studies from around the world, and supported by data collected from the Serious Games Showcase & Challenge this paper aims to set out the fundamental game design principles that support minimalist serious games design, and provide examples of how they can be leveraged to synergistically support existing enterprise solutions to gaming in the field.