While software is so important for all facets of the modern world, software development itself is not a perfect process. Agile methods have recently emerged as a new and different way of developing software as compared to the traditional methodologies. This study surveyed the critical factors related to agile project success using agile application level which has four concepts from the health checklist for agile project. The agile application levels of behaviors, environment, process and techniques were examined their effects to the agile project performance. Agile maturity model also was checked if it affected to their relationships as a moderator. A survey was conducted among agile professionals, gathering survey data from agile practitioners working in the various organizations in Korea. Results from this study reveal that the behaviors, environment, process and techniques of agile project practitioners affect the project performance positively, and agile maturity has the moderation effect on their relationships.