Games like Eternal Vigil: Crystal Defender
Games like Eternal Vigil: Crystal Defender include Hades, Kingdom Rush - Tower Defense, Mount & Blade: Warband, Thronefall, and Mount & Blade II: Bannerlord. We matched them by the tags players give Eternal Vigil: Crystal Defender on Steam (Tower Defense, Hack and Slash, Action, Beat 'em up, and Strategy): closest matches first, and among equally close ones the better-known games.

Hades
Shared: Hack and Slash · Action · Action Roguelike

Kingdom Rush - Tower Defense
Shared: Tower Defense · Strategy · Action

Mount & Blade: Warband
Shared: Strategy · Action · Medieval

Thronefall
Shared: Tower Defense · Strategy · Action

Mount & Blade II: Bannerlord
Shared: Strategy · Medieval · Action

Fatekeeper
Shared: Action · First-Person · Hack and Slash

Hades II
Shared: Action · Hack and Slash · Action Roguelike

Black Myth: Wukong
Shared: Action · RPG · Combat

Kingdom Come: Deliverance II
Shared: Medieval · First-Person · Action

Orcs Must Die!
Shared: Tower Defense · Action · Strategy

God of War
Shared: Action · Hack and Slash · Combat

GemCraft - Chasing Shadows
Shared: Tower Defense · Strategy · Action

Kingdom Rush Origins - Tower Defense
Shared: Tower Defense · Strategy · Tactical

Monsters are Coming!
Shared: Tower Defense · Action · Hack and Slash

We Who Are About To Die
Shared: Action · Strategy · Hack and Slash

Orcs Must Die! 2
Shared: Tower Defense · Action · Strategy

Orcs Must Die! 3
Shared: Tower Defense · Strategy · Action

Mortal Sin
Shared: Hack and Slash · First-Person · Action

Freeman: Guerrilla Warfare
Shared: Action · Strategy · First-Person

MORDHAU
Shared: First-Person · Medieval · Action

Sanctum 2
Shared: Tower Defense · Action · Strategy

Blood of Steel
Shared: Hack and Slash · Strategy · Action

BioShock Infinite
Shared: Action · First-Person · RPG

Wolcen: Lords of Mayhem
Shared: Hack and Slash · Action · RPG