People with Parkinson's disease (PD) can have dysarthria, a voice disorder that affects speech intelligibility. To fight this disorder people may resort to speech and language therapy. Unfortunately, weekly speech therapy sessions may not be enough, because to achieve and maintain good voice quality, intensive training is required. Additionally, the COVID-19 pandemic brought attention to the need for alternative speech therapy treatments that complement face-to-face appointments. Here, we propose a serious therapy game to improve voice loudness that can be used for intensive therapy or when face-to-face appointments are not possible. The game integrates three voice exercises used in speech therapy sessions for people with PD and aims to provide motivation for patients to perform the exercises on a daily basis. This application evaluates the vocal intensity, vocal frequency and maximum phonation time, offering real-time visual feedback. It also allows pathologists to customize the exercises difficulty to the needs of each patient.