Caring for people with Alzheimer disease can be demanding. As an attempt to help caregivers to improve their interaction with people with Alzheimer disease, we are developing a personalized simulation allowing caregivers to practice problematic situations they encounter in their daily life. The strong level of personalization and the large number of interaction choices make it challenging to design interaction mechanisms that are usable for targeted endusers. After several stages of design and evaluation, we propose an interface that supports the strong dynamic interaction during the game, it is integrated into the 3D environment and is simple to be used even by players with limited computer skills.