I thought it was a notable step up from Moon in both its construction and execution. Its able to transcend its plot and the mechanics of a "time travel/parallel universe" conceit and actually reach an emotional catharsis that's pretty sublime. There's a definite Hitchcockian throughline to how Gyllenhaal's character becomes obsessed with his mission and burgeoning love of Monaghan's character (because really, who wouldn't?) all bound by a series of tense set-pieces in the train. Those sequences are levied well by the segments involving Vera Farmiga, whose able to deliver some clunky exposition fairly well. There's a set of well-worn, but well-explored philosophical ideas at play. Any issues I had with it were the moments of exposition, Jeffrey Wright's miscalculated performance, and the direction it takes in the final 5 or so minutes. Aside from that, it's about as enjoyable of a "time travel" film as I've seen in ages.