Games like Spaceman Sparkles 2
Games like Spaceman Sparkles 2 include Hotline Miami, Just Shapes & Beats, LUFTRAUSERS, Katana ZERO, and Bastion. We matched them by the tags players give Spaceman Sparkles 2 on Steam (Action, Bullet Hell, and Indie): closest matches first, and among equally close ones the better-known games.

Hotline Miami
Shared: Action · Great Soundtrack · Indie

Just Shapes & Beats
Shared: Bullet Hell · Great Soundtrack · Action

LUFTRAUSERS
Shared: Bullet Hell · Indie · Action

Katana ZERO
Shared: Action · Great Soundtrack · Indie

Bastion
Shared: Action · Indie · Great Soundtrack

Nuclear Throne
Shared: Indie · Bullet Hell · Action

Hades
Shared: Indie · Action · Great Soundtrack

Touhou Fuujinroku ~ Mountain of Faith.
Shared: Action · Indie · Bullet Hell

UBERMOSH
Shared: Action · Great Soundtrack · Indie

Savant - Ascent
Shared: Action · Indie · Great Soundtrack

ZeroRanger
Shared: Bullet Hell · Indie · Action

Vampire Survivors
Shared: Bullet Hell · Indie · Action

Cuphead
Shared: Great Soundtrack · Indie · Bullet Hell

My Friend Pedro
Shared: Action · Indie · Great Soundtrack

TouHou Makuka Sai ~ Fantastic Danmaku Festival Part II
Shared: Bullet Hell · Indie · Great Soundtrack

Hotline Miami 2: Wrong Number
Shared: Great Soundtrack · Action · Indie

Star Saviors
Shared: Bullet Hell · Action · Indie

Pizza Tower
Shared: Great Soundtrack · Indie · Action

Touhou Koumakyou: New Classic - the Embodiment of Scarlet Devil
Shared: Bullet Hell · Action · Great Soundtrack

Megabonk
Shared: Indie · Bullet Hell · Action

Touhou Kouryudou ~ Unconnected Marketeers.
Shared: Bullet Hell · Action · Great Soundtrack

Jets'n'Guns 2
Shared: Action · Indie · Great Soundtrack

The Void Rains Upon Her Heart
Shared: Bullet Hell · Indie · Action

Touhou Kikeijuu ~ Wily Beast and Weakest Creature.
Shared: Bullet Hell · Indie · Great Soundtrack