Games like Mecha Knights: Nightmare
Games like Mecha Knights: Nightmare include ARMORED CORE™ VI FIRES OF RUBICON™, Titanfall® 2, Call of Duty®, DAEMON X MACHINA, and STAR WARS™ Battlefront II (Classic, 2005). We matched them by the tags players give Mecha Knights: Nightmare on Steam (Mechs, Robots, Singleplayer, Action, and Military): closest matches first, and among equally close ones the better-known games.

ARMORED CORE™ VI FIRES OF RUBICON™
Shared: Mechs · Robots · Action

Titanfall® 2
Shared: Mechs · Singleplayer · Action

Call of Duty®
Shared: Singleplayer · Action · Military

DAEMON X MACHINA
Shared: Mechs · Robots · Action

STAR WARS™ Battlefront II (Classic, 2005)
Shared: Action · Shooter · Singleplayer

Ravenfield
Shared: Singleplayer · Military · Action

Fallout: New Vegas
Shared: Singleplayer · Moddable · Action

Vanquish
Shared: Action · Singleplayer · Mechs

Grand Theft Auto V Legacy
Shared: Action · Singleplayer · Third Person

Bright Memory: Infinite
Shared: Action · Singleplayer · Indie

Mecha BREAK
Shared: Mechs · Robots · Action

Call of Duty®: Black Ops III
Shared: Action · Singleplayer · Shooter

Call of Duty®: Modern Warfare® II
Shared: Action · Singleplayer · Shooter

Arma 3
Shared: Action · Military · Shooter

Battlefield™ 2042
Shared: Singleplayer · Military · Action

DOOM Eternal
Shared: Action · Singleplayer · Shooter

M.A.S.S. Builder
Shared: Mechs · Robots · Indie

Black Mesa
Shared: Action · Singleplayer · Shooter

RoboCop: Rogue City
Shared: Singleplayer · Action · Shooter

Trepang2
Shared: Singleplayer · Shooter · Action

Call of Duty®: Modern Warfare®
Shared: Singleplayer · Action · Military

Half-Life 2
Shared: Action · Singleplayer · Shooter

Five Nights at Freddy's: Security Breach
Shared: Singleplayer · Robots · Horror

STAR WARS™ Jedi Knight - Jedi Academy™
Shared: Action · Singleplayer · Third Person