Borderline certainly has its moments, especially in the first and second acts, with events unfolding at a rapid pace and characters getting established. I could easily buy Samara Weaving as a 90s pop star (who needed to sing a lot more in the film), Ray Nicholson as a romantic stalker-sociopath (man, this guy's got the presence and the "killer" smile!), and Eric Dane as a bodyguard (somehow, the protagonist?). Alba Baptista also gets a notably wacky role. The performances are pretty good, the lighting choices are great, and the colour palette is interesting. And oh yes, I really enjoyed the soundtrack.
What doesn't hit a home-run, for me, is basically the watered-down third act (..even when there are enough stabbings and some darkly funny moments). The film desperately needed more of Ray Nicholson than the rest, but the man simply chews up the scenery whenever he's present. The showdown between Samara Weaving and Alba Baptista was enjoyable. It's just that the film can't entirely stick the landing in terms of its tonality, thereby not ending up as memorable given the potential we see early on. Also, they didn't give the romance angle (between Sofia & Rhodes) any real build-up, and it ends up looking weak as hell.