Games like PhD
Games like PhD include Door Kickers, Children of the Sun, Door Kickers 2: Task Force North, Zup! S, and Mini Metro. We matched them by the tags players give PhD on Steam (Action, Strategy, Arcade, Puzzle, and Exploration): closest matches first, and among equally close ones the better-known games.

Door Kickers
Shared: Strategy · Action · Top-Down

Children of the Sun
Shared: Action · Strategy · Arcade

Door Kickers 2: Task Force North
Shared: Action · Real Time Tactics · Strategy

Zup! S
Shared: Puzzle · 2D · Minimalist

Mini Metro
Shared: Strategy · Puzzle · Minimalist

UFO 50
Shared: Action · Arcade · Strategy

The Escapists
Shared: Strategy · Action · 2D

Zuma Deluxe
Shared: Arcade · Puzzle · Strategy

Gunpoint
Shared: Puzzle · Action · 2D

Word Game
Shared: Puzzle · Strategy · Exploration

Turnip Boy Commits Tax Evasion
Shared: Puzzle · Exploration · Action

I, Zombie
Shared: Puzzle · Strategy · Top-Down

Zup!
Shared: Puzzle · 2D · Minimalist

Aliens: Dark Descent
Shared: Strategy · Action · Real Time Tactics

Linelith
Shared: Strategy · Puzzle · Exploration

Reassembly
Shared: Strategy · Action · 2D

GemCraft - Chasing Shadows
Shared: Strategy · Action · Top-Down

Mount & Blade II: Bannerlord
Shared: Strategy · Action · Character Customization

Peggle Deluxe
Shared: Arcade · Puzzle · 2D

BEEP
Shared: Action · Puzzle · 2D

Mini Motorways
Shared: Strategy · Puzzle · Minimalist

Waveform
Shared: Puzzle · Strategy · Arcade

Windowkill
Shared: Action · Arcade · 2D

Monument Valley 2
Shared: Strategy · Action · Puzzle