My current People Playground mod-enabled obsession is the “Facility Escape”. The background for this RP is simple: A character from another setting is trapped in the mysterious mad science super-facility and has to try and escape, fighting their way past an army of workers, security contractors, androids, and who knows what else.
Characters from settings as distinct as Undertale and Hotline Miami have been placed in the playground. The (intentional) clumsiness of the human figures just, if anything adds to the fun. There’s nothing like jury-rigging an “epic” sword vs. chainsaw battle.
Characters who have “earned the privilege” of escaping have the final exit simulated by a black hole being created with them sucked in. This symbolizes a portal to their home setting (or somewhere else?) being activated.