Games like Parhelion
Games like Parhelion include Undertale, DAVE THE DIVER, Vampire Survivors, To the Moon, and DELTARUNE. We matched them by the tags players give Parhelion on Steam (RPG, Singleplayer, Pixel Graphics, Interactive Fiction, and Cartoony): closest matches first, and among equally close ones the better-known games.

Undertale
Shared: Pixel Graphics · RPG · Singleplayer

DAVE THE DIVER
Shared: Pixel Graphics · Singleplayer · Casual

Vampire Survivors
Shared: Pixel Graphics · Singleplayer · 2D

To the Moon
Shared: Pixel Graphics · Singleplayer · Interactive Fiction

DELTARUNE
Shared: Pixel Graphics · RPG · Singleplayer

Stardew Valley
Shared: Pixel Graphics · RPG · Singleplayer

Impostor Factory
Shared: Pixel Graphics · RPG · Singleplayer

Finding Paradise
Shared: Pixel Graphics · RPG · Singleplayer

Stoneshard
Shared: RPG · Pixel Graphics · Singleplayer

Graveyard Keeper
Shared: RPG · Pixel Graphics · Singleplayer

Touhou Mystia's Izakaya
Shared: Pixel Graphics · RPG · Casual

OneShot
Shared: Pixel Graphics · Singleplayer · Choices Matter

A Bird Story
Shared: Pixel Graphics · Singleplayer · Interactive Fiction

Eastward
Shared: Pixel Graphics · Singleplayer · RPG

OCTOPATH TRAVELER™
Shared: RPG · Pixel Graphics · Singleplayer

Storyteller
Shared: Interactive Fiction · 2D · Singleplayer

Yes, Your Grace
Shared: RPG · Pixel Graphics · Choices Matter

Melvor Idle
Shared: RPG · Singleplayer · Casual

Pocket Mirror ~ GoldenerTraum
Shared: RPG · Pixel Graphics · 2D

The Witcher 3: Wild Hunt — Remastered
Shared: RPG · Singleplayer · Choices Matter

CrossCode
Shared: RPG · Pixel Graphics · Singleplayer

Drova - Forsaken Kin
Shared: RPG · Pixel Graphics · 2D

Always Sometimes Monsters
Shared: RPG · Pixel Graphics · Singleplayer

Kingdom Rush Origins - Tower Defense
Shared: Singleplayer · 2D · Casual