Quite a few things would need to be changed . I've compiled a list (BTW, I'm basing this on a possible TV series) 1. Sleeker, more human designs: Characters would have to look the part of a biomechanical being, with a more proportionally human figure. 2. Change setting: This may sound a bit drastic, but it really isn't. There would just need to be more of a sci fi element to the story. Not as much open wilderness, and more integration with Metru-Nui style technology. 3. Villians: They'd have to be MUCH creepier. Rahkshi: go all out. Spines, poison, tongues, jawless maws, everything. Same with Visorak and Barraki. 4. Powers: Less of a focus on elemental powers. Possibly even replace them with less close-to-omnipotent powers, even possibly just their mask powers ('cus I mean, judging by the theories in this forum, most Toa are super-powered). 5. Phasers: To make up for fewer powers, and to add some thrill of a fire-fight, add phasers you can set to stun. 6. More mature jokes: Bionicle has some pretty lame jokes. You'd need to make 'em mature to appeal to a more adult audience. 7. Romance: This is pretty much a requirement for a young adult or adult audience. No romance = no interest. I'm probably missing quite a bit, but Bionicle would have to change quite a bit to fit into a TV series that would appeal to adults (however, I would LOVE to watch it).