## 2 Materials and Methods
### Parabolic Basketball VR  
An interdisciplinary team dedicated to developing a serious game on projectile motion was formed with the participation of various professional figures [44]: a physics professor responsible for providing pedagogical guidance on key concepts, a serious game designer focused on creating clear and educational gameplay mechanics, a participant experience researcher to organize testing sessions, two game programmers who developed prototypes, and four participants (two teachers and two students) who provided direct feedback on the system. Over a period of two months, this team held weekly meetings to discuss game requirements, explore applicable technologies, and define project scope. The project culminated in the creation of a prototype in the Unity game engine, based on ideas generated throughout this collaborative process. For the preliminary design of the IVR serious game, a proactive approach to improving projectile motion teaching was proposed. Initially, an online questionnaire was proposed to physics students at the UTP, seeking to understand their limitations and motivations regarding the study of this physical phenomenon. Based on this information, a structured development model was implemented in three phases: requirements analysis, prototyping, and evaluation [45]. This methodology allowed for the identification of the needs and preferences of the involved students and teachers, facilitating the creation of an educational serious game centered on projectile motion. The result was \"Parabolic Basketball VR\"--an IVR serious game designed to teach projectile motion through a basketball game in which players must score baskets from different positions, demonstrating how launch angle and velocity affect the ball's trajectory [21]. Developed in Unity 3D and designed to be played on the Oculus Quest 2, the game aimed to balance entertainment with learning (See Figure 2) [46]. Playtesting sessions were organized with specific target groups: teachers and students. These sessions aimed to iterate on playable prototypes to improve gameplay and align the game more closely with educational objectives [47]. Playtests were conducted in two phases, first with teachers to obtain expert evaluations of the game's alignment with educational objectives and then with students to gather impressions on gameplay and practical learning. Each playtest session was recorded on video to facilitate a detailed  
Figure 1: Schematic design of the educational serious game “Parabolic Basketball VR”. Game Mechanics and Learning Approach  
The serious game \"Parabolic Basketball VR\" was designed as an educational tool for teaching projectile motion to university students, integrating a realistic simulation environment with interactive gameplay mechanics. Inspired by basketball, the serious game places the user as the protagonist inside a virtual stadium, where they must execute ball throws while adjusting key variables such as launch angle and velocity. The physics simulation of the ball's behavior has been developed using precise equation programming to accurately reflect parabolic trajectories in a gamified context. Additionally, the design of the environment and objects, such as the hoop, backboard, and ball, follows a semi-realistic 3D aesthetic, ensuring an immersive experience that reinforces the learning of fundamental physics concepts. The serious game is structured into two main phases: Training and Practice. In the Training phase, students receive instructions on the principles of projectile motion, the variables influencing the ball's trajectory, and how these can be manipulated within the game. Interactive explanations are provided alongside visual simulations, allowing students to observe how the initial velocity and launch angle affect the projectile's path. During the Practice phase, players must score from different positions around the court, adjusting their shots based on prior learning.