Build a multiplayer game prototype

We are working on a 3D multiplayer action game with a cenital or angled camera in which players explore a level, evading traps and trying to obtain the most treasures posible. A random treasure in the game will be cursed and, if obtained, the player who obtained the cursed treasure will be transformed into a monster and a timer will start. From that moment on, the player who was transformed into a monster has to pursue the other players until the timer ends. If the monster catches other players, those players become monsters too. In the end (which happens after the timer that started when the first monster appears ends), players will be rewarded for the amount of treasures found, time untransformed while a monster roams the level and players captured as a monster.