With the online-everything transformation accelerated by a global Covid-19 pandemic, we may finally find ourselves on the verge of the next potentially paradigm-shifting step after the mobile Internet: The Metaverse. Among others, the Metaverse will utilize head-mounted devices (HMDs) and extended reality (XR), including but not limited to virtual and augmented reality (VR/AR), as the medium to connect avatars and users in the real world. In addition, the Metaverse is supposed to provide gamified experiences around emerging Web 3.0 technologies and is anticipated to be the precursor of the so-called Multiverse, which will serve as an architecture of advanced XR experience realms. In this paper, we focus on the anticipated 6G post-smartphone era, where smart wearables such as VR/AR HMDs are increasingly replacing the functionalities of smartphones. Our contributions are threefold: (i) we first extend Metaverse's primary focus on VR/AR to Multiverse's advanced XR realms of experience. Next, we gamify and implement all eight Multiverse realms of experience using Oculus Quest 2 and Microsoft HoloLens 2 as state-of-the-art VR/AR HMDs, experimentally investigating and comparing the performance of a (ii) single-player origami game and (iii) multi-player maze game across our proposed integrated VR/AR HMD and Amazon Mechanical Turk crowd-of-Oz (CoZ) platform.INDEX TERMS 6G post-smartphone era, crowd-of-Oz (CoZ), extended reality (XR), gamified experiences, head-mounted devices (HMDs), Metaverse, multiverse, web 3.0.