Games like Double Spoiler
Games like Double Spoiler include Touhou Koumakyou: New Classic - the Embodiment of Scarlet Devil, Touhou Tenkuushou ~ Hidden Star in Four Seasons., TouHou Makuka Sai ~ Fantastic Danmaku Festival Part II, Touhou Fuujinroku ~ Mountain of Faith., and Hollow Knight: Silksong. We matched them by the tags players give Double Spoiler on Steam (Indie, Action, Bullet Hell, Shoot 'Em Up, and Faith): closest matches first, and among equally close ones the better-known games.
Touhou Koumakyou: New Classic - the Embodiment of Scarlet Devil
Shared: Bullet Hell · Shoot 'Em Up · Action
Touhou Tenkuushou ~ Hidden Star in Four Seasons.
Shared: Bullet Hell · Indie · Shoot 'Em Up
TouHou Makuka Sai ~ Fantastic Danmaku Festival Part II
Shared: Indie · Bullet Hell · Shoot 'Em Up
Touhou Fuujinroku ~ Mountain of Faith.
Shared: Indie · Action · Bullet Hell
Hollow Knight: Silksong
Shared: Indie · Great Soundtrack · Difficult
Touhou Kouryudou ~ Unconnected Marketeers.
Shared: Bullet Hell · Action · Shoot 'Em Up
Touhou Kanjuden ~ Legacy of Lunatic Kingdom.
Shared: Bullet Hell · Indie · Faith
Touhou Kikeijuu ~ Wily Beast and Weakest Creature.
Shared: Indie · Bullet Hell · Shoot 'Em Up
Cuphead
Shared: Indie · Difficult · Great Soundtrack
Touhou Chireiden ~ Subterranean Animism.
Shared: Indie · Action · Bullet Hell
Touhou Juuouen 〜 Unfinished Dream of All Living Ghost.
Shared: Action · Bullet Hell · Shoot 'Em Up
TouHou Makuka Sai ~ Fantastic Danmaku Festival
Shared: Indie · Bullet Hell · Action
ZeroRanger
Shared: Indie · Shoot 'Em Up · Bullet Hell
Just Shapes & Beats
Shared: Bullet Hell · Great Soundtrack · Indie
Touhou Shinreibyou ~ Ten Desires.
Shared: Indie · Action · Bullet Hell
LUFTRAUSERS
Shared: Indie · Bullet Hell · Action
Touhou Kishinjou ~ Double Dealing Character.
Shared: Indie · Bullet Hell · Action
Celeste
Shared: Indie · Great Soundtrack · Difficult
Touhou Seirensen ~ Undefined Fantastic Object.
Shared: Indie · Action · Bullet Hell
The Void Rains Upon Her Heart
Shared: Indie · Bullet Hell · Action
BLUE REVOLVER
Shared: Indie · Bullet Hell · Shoot 'Em Up
Star Saviors
Shared: Action · Bullet Hell · Indie
Touhou Kinjoukyou ～ Fossilized Wonders.
Shared: Bullet Hell · Action · Shoot 'Em Up
Hollow Knight
Shared: Indie · Great Soundtrack · Difficult