Games like Infferno
Games like Infferno include Broforce, Cuphead, Enter the Gungeon, Overcooked! 2, and Left 4 Dead 2. We matched them by the tags players give Infferno on Steam (Action, Indie, Multiplayer, Local Co-Op, and Horror): closest matches first, and among equally close ones the better-known games.

Broforce
Shared: Action · Local Co-Op · Co-op

Cuphead
Shared: Difficult · Local Co-Op · Co-op

Enter the Gungeon
Shared: Indie · Difficult · Local Co-Op

Overcooked! 2
Shared: Multiplayer · Local Co-Op · Co-op

Left 4 Dead 2
Shared: Multiplayer · Co-op · Action

The Outlast Trials
Shared: Multiplayer · Horror · Co-op

Monster Hunter: World
Shared: Action · Multiplayer · Co-op

Gang Beasts
Shared: Multiplayer · Action · Co-op

Resident Evil 5
Shared: Action · Co-op · Horror

Resident Evil 6
Shared: Action · Co-op · Horror

Dead by Daylight
Shared: Multiplayer · Horror · Co-op

Wizard of Legend
Shared: Action · Local Co-Op · Pixel Graphics

Escape the Backrooms
Shared: Multiplayer · Horror · Co-op

Risk of Rain (2013)
Shared: Indie · Action · Pixel Graphics

Human Fall Flat
Shared: Multiplayer · Co-op · Action

Barotrauma
Shared: Multiplayer · Co-op · Horror

GTFO
Shared: Horror · Multiplayer · Co-op

Streets of Rogue
Shared: Multiplayer · Action · Indie

PICO PARK
Shared: Multiplayer · Local Co-Op · Co-op

Phasmophobia
Shared: Multiplayer · Horror · Co-op

Bread & Fred
Shared: Local Co-Op · Co-op · Multiplayer

Risk of Rain 2
Shared: Multiplayer · Action · Co-op

Hero Siege
Shared: Multiplayer · Pixel Graphics · Co-op

Resident Evil Revelations 2
Shared: Multiplayer · Action · Horror