Games like NRG
Games like NRG include Brawlhalla, skate., Pixel Gun 3D: PC Edition, Trailmakers, and BattleBlock Theater®. We matched them by the tags players give NRG on Steam (Platformer, Combat, Colorful, Action, and Character Customization): closest matches first, and among equally close ones the better-known games.

Brawlhalla
Shared: Platformer · Action · Co-op

skate.
Shared: Action · Character Customization · Online Co-Op

Pixel Gun 3D: PC Edition
Shared: Action · Combat · Character Customization

Trailmakers
Shared: Action · Family Friendly · Online Co-Op

BattleBlock Theater®
Shared: Platformer · Co-op · Online Co-Op

Monster Hunter Wilds
Shared: Action · Online Co-Op · Character Customization

Dota 2
Shared: Action · Online Co-Op · PvP

MONSTER HUNTER RISE
Shared: Action · Character Customization · Online Co-Op

Paladins®
Shared: Action · Online Co-Op · PvP

Spelunky 2
Shared: Platformer · Online Co-Op · Co-op

War Thunder
Shared: Action · Combat · Co-op

GrandChase
Shared: Action · Online Co-Op · Character Customization

Mecha BREAK
Shared: Combat · Action · Character Customization

Broforce
Shared: Action · Platformer · Co-op

No Rest for the Wicked
Shared: Combat · Online Co-Op · Character Customization

Trine 2: Complete Story
Shared: Platformer · Co-op · Online Co-Op

PEAK
Shared: Online Co-Op · Co-op · Character Customization

Counter-Strike 2
Shared: Action · Online Co-Op · PvP

Stick It to the Stickman
Shared: Action · Combat · Platformer

Unravel
Shared: Action · Platformer · Colorful

Lords of the Fallen
Shared: Combat · Online Co-Op · Action

Friends vs Friends
Shared: Action · Online Co-Op · Colorful

Geometry Dash
Shared: Platformer · Colorful · Character Customization

Overcooked! 2
Shared: Online Co-Op · Co-op · Action