18 Best PS4 Games You're Not Playing

18. ECHO

Even just as a concept, newcomers Ultra Ultra's stealth game ECHO is genius.

Predicated on the idea of infiltrating a series of gorgeous spaceship interiors where copies of yourself patrol the halls, every action you take to evade or kill will be learned and used against you next time around.

Say you get spotted and leapt off a balcony to safety - next time your pursuers will do the same and land next to you. Choking out an enemy means they know how to defend against it next time, trying to shoot or throw distractions means they'll zero-in your position or fire back - it really makes you rethink how to get through any given level, and ultimately feels like a more intricate version of fighting one of the T-X from Terminator 3.

Story-wise, ECHO is almost high concept "What's real and what's not?" stuff for the sake of it, but with such a meticulously designed heart beating away at the centre, manages to execute on a phenomenally original idea in such an effective way.