Games like Railhold
Games like Railhold include Thronefall, Until We Die, DG2: Defense Grid 2, Creeper World 4, and Aliens: Dark Descent. We matched them by the tags players give Railhold on Steam (Strategy, Action, Tower Defense, Action Roguelike, and Real Time Tactics): closest matches first, and among equally close ones the better-known games.

Thronefall
Shared: Strategy · Tower Defense · Action

Until We Die
Shared: Strategy · Tower Defense · Action

DG2: Defense Grid 2
Shared: Strategy · Tower Defense · Action

Creeper World 4
Shared: Tower Defense · Real Time Tactics · Strategy

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

Frostpunk
Shared: Strategy · Post-apocalyptic · Building

They Are Billions
Shared: Strategy · Tower Defense · Building

Tower Dominion
Shared: Strategy · Tower Defense · Roguelite

Cult of the Lamb
Shared: Action Roguelike · Roguelite · Strategy

Total War: WARHAMMER III
Shared: Strategy · Real Time Tactics · Action

Bloons TD 6
Shared: Strategy · Tower Defense · 3D

Monsters are Coming!
Shared: Action · Tower Defense · Roguelite

Hades
Shared: Action Roguelike · Action · Roguelite

Emberward
Shared: Strategy · Tower Defense · Roguelite

Rogue Tower
Shared: Strategy · Tower Defense · 3D

Artisan TD
Shared: Strategy · Tower Defense · Real Time Tactics

Age of Darkness: Final Stand
Shared: Tower Defense · Strategy · 3D

Megabonk
Shared: Action Roguelike · Roguelite · Action

Infection Free Zone
Shared: Strategy · Post-apocalyptic · Management

Kingdom Two Crowns
Shared: Tower Defense · Strategy · Building

MINOS
Shared: Strategy · Tower Defense · Roguelite

Hades II
Shared: Action · Roguelite · Action Roguelike

Taur
Shared: Strategy · Tower Defense · Action

Shadow Tactics: Blades of the Shogun
Shared: Strategy · Real Time Tactics · Action