Just dumb, really dumb. Tonally it is all over the place, one second it's all bright shinny colours with Alan Silvestri style blockbuster score an upbeat tale of can-do genius inventor kids from the inner city, next second it's gritty gangsters and in your face black lives matter genius kids throwing all common sense out the window for hackneyed time travel save the day. And then it just stops. Not in an ambiguous way, just a kind of, hmm what else can we say about white cops shooting black teens for no reason, nothing more, okay let's just wrap it up then. Dumb, preachy, doesn't follow it'...