The one playing ingame. 

So far, only the album version was uploaded until now.

Shape Memory Alloys Game Version - Armored Core Soundtrack

Dotted Line - Armored Core Soundtrack

Insurance Money - Armored Core Soundtrack

14 - 9 - Armored Core Master of Arena Soundtrack

Armored Core: Nine Breaker Soundtrack

Kota Hoshino

Steroid

Armored Core Nexus Original Soundtrack

Lead Composer: Kota Hoshino
Composer: N.O.Y.B. (Kota Hoshino, Yukinori Takada, Tsukasa Saitoh), Yuji Kanda, Keiichiro Segawa
Arranger: Kota Hoshino, Shohei Tsuchiya, Kohichi Suenaga, Yukinori Takada
Lyricist: Kota Hoshino

Disc 2 - Memories

First Summer

Sakin - Blue Sky (Night Sky Mix)

Welcome to the Sh*t Show 🤘🏻

Made by BЯΛD ⛧

Sh*t Show

If you're a fan of the Armored Core series then you would recognize this awesome tune, enjoy 

Shape Memory Alloys Game Version - Armored Core Soundtrack

PsycoDevil