Games like Adventure Rush
Games like Adventure Rush include Vampire Survivors, BALL x PIT, Nova Drift, Touhou Hero of Ice Fairy, and Halls of Torment. We matched them by the tags players give Adventure Rush on Steam (Side Scroller, Bullet Hell, Mystery Dungeon, Shoot 'Em Up, and Collectathon): closest matches first, and among equally close ones the better-known games.

Vampire Survivors
Shared: Bullet Hell · Roguelite · Arcade

BALL x PIT
Shared: Bullet Hell · Roguelite · Arcade

Nova Drift
Shared: Bullet Hell · Shoot 'Em Up · Roguelite

Touhou Hero of Ice Fairy
Shared: Bullet Hell · Side Scroller · Roguelite

Halls of Torment
Shared: Bullet Hell · Roguelite · Roguelike

Megabonk
Shared: Bullet Hell · Roguelite · Roguelike

Rogue Legacy 2
Shared: Arcade · Roguelite · Side Scroller

Death Must Die
Shared: Bullet Hell · Roguelite · RPG

Touhou Luna Nights
Shared: Side Scroller · Bullet Hell · Action-Adventure

Skul: The Hero Slayer
Shared: Roguelite · Side Scroller · Roguelike

20 Minutes Till Dawn
Shared: Bullet Hell · Shoot 'Em Up · Roguelite

Rabi-Ribi
Shared: Bullet Hell · Side Scroller · Female Protagonist

Star of Providence
Shared: Bullet Hell · Roguelite · Shoot 'Em Up

Brotato
Shared: Bullet Hell · Roguelike · Roguelite

I Am Legion: Stand Survivors
Shared: Bullet Hell · Shoot 'Em Up · Roguelite

Soulstone Survivors
Shared: Bullet Hell · Roguelite · Roguelike

Bit Blaster XL
Shared: Bullet Hell · Shoot 'Em Up · Arcade

Greedland
Shared: Shoot 'Em Up · Bullet Hell · Roguelite

One Way Heroics
Shared: Side Scroller · Mystery Dungeon · Roguelite

Enter the Gungeon
Shared: Bullet Hell · Roguelike · Indie

Rogue Legacy
Shared: Roguelike · Side Scroller · Roguelite

Magicraft
Shared: Bullet Hell · Roguelite · Roguelike

Boneraiser Minions
Shared: Bullet Hell · Roguelite · Arcade

Touhou Tenkuushou ~ Hidden Star in Four Seasons.
Shared: Bullet Hell · Shoot 'Em Up · Arcade