Games like Reaper's Interin Program (R.I.P.)
Games like Reaper's Interin Program (R.I.P.) include Vampire Survivors, Enter the Gungeon, Brotato, Skul: The Hero Slayer, and Megabonk. We matched them by the tags players give Reaper's Interin Program (R.I.P.) on Steam (Action, Roguelike, Action Roguelike, Bullet Hell, and 2D): closest matches first, and among equally close ones the better-known games.

Vampire Survivors
Shared: Action Roguelike · Bullet Hell · 2D

Enter the Gungeon
Shared: Roguelike · Action Roguelike · Bullet Hell

Brotato
Shared: Roguelike · Action Roguelike · Bullet Hell

Skul: The Hero Slayer
Shared: Action · Action Roguelike · Roguelike

Megabonk
Shared: Roguelike · Action Roguelike · Bullet Hell

BALL x PIT
Shared: Action · Roguelike · Bullet Hell

Halls of Torment
Shared: Action Roguelike · Bullet Hell · Roguelike

Dead Cells
Shared: Roguelike · Action Roguelike · 2D

The Binding of Isaac: Rebirth
Shared: Roguelike · Action Roguelike · Singleplayer

Death Must Die
Shared: Action Roguelike · Bullet Hell · Action

Hades
Shared: Action Roguelike · Action · Roguelike

Tower of Babel: Survivors of Chaos
Shared: Action Roguelike · Bullet Hell · Roguelike

Rogue Legacy
Shared: Roguelike · Action · Action Roguelike

Nuclear Throne
Shared: Roguelike · Action Roguelike · Action

Returnal™
Shared: Action · Roguelike · Bullet Hell

Dungreed
Shared: Action Roguelike · Roguelike · Action

The Binding of Isaac
Shared: Roguelike · Action Roguelike · Action

Hades II
Shared: Action · Roguelike · Action Roguelike

Soulstone Survivors
Shared: Action Roguelike · Bullet Hell · Roguelike

Have a Nice Death
Shared: Action Roguelike · Action · 2D

Rabbit and Steel
Shared: Action Roguelike · Bullet Hell · Roguelike

Risk of Rain (2013)
Shared: Roguelike · Action Roguelike · Action

Risk of Rain 2
Shared: Action Roguelike · Roguelike · Action

Noobs Want to Live
Shared: Roguelike · Action · Bullet Hell