The challenge of operating and managing complex and dynamic environments, known as complex endeavors, has become a central issue in the C2 research community. NATO research groups have studied how to combat the negative effects of endeavor complexity on performance. Essential to these efforts is the study of C2 Agility, which is the ability of an entity to cope with change and employ different C2 approaches based on the requirements imposed by—and changes in—the current operational environment. An important aspect in accomplishing this research goal is to study how operational environments are constituted, as this would enable research into how the effectiveness of different C2 approaches is affected by different endeavors. The Endeavor Space model, which represents endeavor complexity in three dimensions, was developed for this purpose. In an effort to continue research on the Endeavor Space, the current study set out to implement the dimensions in a C2 research platform called ELICIT. Three ELICIT scenarios were created to represent different regions of the Endeavor Space. Additionally, the study designed, developed, and tested a prototype self-assessment instrument—the ESSAI—to capture how the Endeavor Space dimensions—Tractability, Dynamics, and Dependencies—were experienced by operators. Eight teams completed the scenarios and rated their complexity using the ESSAI. No significant differences in perceived complexity could be found between the scenarios. However, all Endeavor Space dimensions indicated correlational relationships with perceived difficulty, and most of them correlated with ELICIT performance. This is indicative of underlying patterns that were not thoroughly revealed in the current study. Implications and improvements for future research are discussed.