Instructions are an important aspect of virtual reality serious games since they are crucial to understanding what is expected from the user. User friendly instructions can contribute positively to the user experience, while confusing instructions can degrade it. There are various methods of instruction giving. In this study, we examine the effects of four different instruction methods on user experience in virtual reality serious games. The four instruction methods that were explored in our study are 3D animated, pictograph, written and verbal instructions. Eight simple vocational tasks were designed and implemented to be performed in an immersive virtual warehouse environment. A user study was performed with 15 adult participants. Results revealed that animated instructions provided better user experience among the four methods. Pictograph and written instructions shared similar mid-range rankings. Verbal instructions were the least preferred method. In this paper, we present our experiment design, results and discussions of our implications for future virtual reality serious game studies.