Games like Neon Frontline
Games like Neon Frontline include Slay the Spire, Balatro, Slay the Spire 2, Monster Train, and Wildfrost. We matched them by the tags players give Neon Frontline on Steam (Roguelike Deckbuilder, Strategy, Card Battler, Turn-Based Tactics, and Deckbuilding): closest matches first, and among equally close ones the better-known games.

Slay the Spire
Shared: Roguelike Deckbuilder · Card Battler · Strategy

Balatro
Shared: Roguelike Deckbuilder · Strategy · Roguelike

Slay the Spire 2
Shared: Strategy · Roguelike Deckbuilder · Roguelike

Monster Train
Shared: Card Battler · Turn-Based Tactics · Deckbuilding

Wildfrost
Shared: Roguelike Deckbuilder · Card Battler · Turn-Based Tactics

Monster Train 2
Shared: Roguelike Deckbuilder · Strategy · Deckbuilding

Touhou: Lost Branch of Legend
Shared: Roguelike Deckbuilder · Strategy · Card Battler

LONESTAR
Shared: Strategy · Roguelike Deckbuilder · Card Battler

Cobalt Core
Shared: Roguelike Deckbuilder · Strategy · Card Game

9 Kings
Shared: Strategy · Roguelike Deckbuilder · Roguelike

Dungeons & Degenerate Gamblers
Shared: Roguelike Deckbuilder · Strategy · Roguelike

As We Descend
Shared: Roguelike Deckbuilder · Card Battler · Deckbuilding

Dicey Dungeons
Shared: Roguelike Deckbuilder · Card Battler · Deckbuilding

Die in the Dungeon
Shared: Strategy · Roguelike Deckbuilder · Roguelike

Vampire Crawlers: The Turbo Wildcard from Vampire Survivors
Shared: Card Battler · Strategy · Deckbuilding

Inscryption
Shared: Card Battler · Deckbuilding · Card Game

StarVaders
Shared: Roguelike Deckbuilder · Turn-Based Tactics · Deckbuilding

Alina of the Arena
Shared: Roguelike Deckbuilder · Turn-Based Tactics · Roguelike

Dream of Corpse Lady
Shared: Strategy · Card Battler · Card Game

Astrea: Six-Sided Oracles
Shared: Roguelike Deckbuilder · Card Battler · Strategy

Across the Obelisk
Shared: Roguelike Deckbuilder · Turn-Based Strategy · Card Battler

Shogun Showdown
Shared: Roguelike Deckbuilder · Roguelike · Strategy

DICEOMANCER
Shared: Strategy · Roguelike Deckbuilder · Card Battler

RACCOIN: Coin Pusher Roguelike
Shared: Strategy · Roguelike Deckbuilder · Deckbuilding