The use of learning games implies they can provide the teachers with an answer to the lack of awareness often reported for such systems. The monitoring of the activity is indeed a central task for teachers that can be carried out only if key elements related to an ongoing pedagogical activity are reported. In this paper, we propose a solution based on the users' traces that are transformed and displayed for the teacher through indicators. We also discuss how the monitoring actions are in a sense connected with these indicators. The approach is illustrated through three use cases, paying particular attention to the teachers' needs and to collaborative aspects.