The design of handheld interactive devices in science fiction video games often prioritizes visual impact over usability, limiting their plausibility as future technology visions. To investigate the topic, we used physical prototyping and user evaluation to critically examine how such fictional devices might function if realized. We selected 20 devices from popular science fiction games and conducted a visual thematic analysis. Focus groups evaluated both device images and full-scale physical prototypes of one device and redesigned variants. The findings show that many in-game devices suffer from poor ergonomics and unclear interfaces, but small design adjustments, such as relocating buttons or reshaping grips, can improve perceived usability without breaking narrative immersion. This work introduces a user-centered approach to evaluating speculative virtual objects and offers Human Computer Interaction (HCI) researchers and game designers a method for grounding future technology visions in practical interaction concerns.