We developed a hand-held controller named DexController, leveraging grasp as an additional input modality for virtual reality(VR) game. The pressure-sensitive surface of DexController could recognize two different grasp-poses (i.e. precision grip and power grip) and detect grasp-force. For demonstration, we designed a VR defense game in which players should attack different virtual enemies using the proper weapon with a proper level of force. User study confirmed that utilizing meaningful information of grasping facilitates natural mapping with game contents, which led VR game users to experience enhanced presence and enjoyment.