Gamification aims to implement game features in non-game contexts, with the goal of increasing the motivation of individuals performing a specific task or set of tasks. The tasks themselves, can focus on cognitive behavior change (e.g., overcoming anxiety) or physical behavior change (e.g., overcoming a shoulder injury). Current gamification methods primarily serve as guidelines and principles for the design of gamified applications. Moreover, these methods often overlook the complexity of actually implementing the game features and do not consider the effects that game features have on individuals' ability to perform a target task. A knowledge gap exists in understanding the tradeoffs between the complexity of implementing a game feature and the impact it has on increasing individuals' motivation and performance on a particular task or set of tasks. This paper presents a method for evaluating the complexity of implementing game features and the physical effort required to perform the tasks of the application, with a specific focus on physically-interactive gamified applications. Designers will gain a fundamental understanding of how the implementation of specific game features, contributes toward the objective of the application. A case study is presented that focuses on physically-interactive gamified applications in a virtual environment. Empirical results measuring the effects of game features on participants' performance are presented, which provide evidence in support of the metrics proposed in this study. Knowledge gained from this work will inform designers on how to manage their resources more efficiently and predict possible design issues (e.g., not meeting the objective of the application) while creating gamification applications. (C) 2017 Elsevier Ltd. All rights reserved.