If you loved Self/less, try Alien Outpost
A bridge between a film you've already seen and one most people haven't. Alien Outpost has roughly 13.1× fewer votes than Self/less — it's a deeper cut, not a mainstream recommendation. Here's what they share, and what the second one does that the first one doesn't.
What they share
Theyboth carry the paranoid mood tag, and they sit in Action / Science Fiction / Thriller territory. If that's the register that drew you to Self/less, the second film will land in a comparable space — through a different lens.
What Alien Outpost is
Eastern Europe. Late autumn. Distant gunfire. Soldiers guard a lonely outpost after a decade of quelling an alien invasion. When one of the men discovers the aliens are regrouping, paranoia infects the unit. Raisani's film is a tense, low-budget riff on better-known invasion stories.

