Games like H.A.R.D.
Games like H.A.R.D. include Celeste, Super Meat Boy, Geometry Dash, Downwell, and VVVVVV. We matched them by the tags players give H.A.R.D. on Steam (Precision Platformer, Difficult, 2D Platformer, Singleplayer, and Platformer): closest matches first, and among equally close ones the better-known games.
Celeste
Shared: Precision Platformer · Difficult · 2D Platformer
Super Meat Boy
Shared: Precision Platformer · Difficult · Platformer
Geometry Dash
Shared: Difficult · Precision Platformer · Singleplayer
Downwell
Shared: Precision Platformer · Platformer · 2D Platformer
VVVVVV
Shared: Precision Platformer · 2D Platformer · Platformer
Hollow Knight
Shared: Difficult · Platformer · Singleplayer
Jump King
Shared: Difficult · Precision Platformer · Platformer
Braid
Shared: 2D Platformer · Platformer · Singleplayer
LIMBO
Shared: Platformer · Puzzle Platformer · Singleplayer
Hollow Knight: Silksong
Shared: Difficult · Singleplayer · Platformer
SANABI
Shared: 2D Platformer · Singleplayer · Pixel Graphics
Thomas Was Alone
Shared: Precision Platformer · Platformer · 2D Platformer
The End Is Nigh
Shared: Precision Platformer · Difficult · Platformer
A Dance of Fire and Ice
Shared: Difficult · Singleplayer · Arcade
Defy Gravity Extended
Shared: Platformer · Singleplayer · Difficult
Rain World
Shared: Difficult · Platformer · 2D Platformer
Pizza Tower
Shared: 2D Platformer · Platformer · Singleplayer
Getting Over It with Bennett Foddy
Shared: Difficult · Singleplayer · Platformer
N++ (NPLUSPLUS)
Shared: Precision Platformer · Difficult · 2D Platformer
Katana ZERO
Shared: Platformer · 2D Platformer · Pixel Graphics
Dungeon Escape
Shared: Precision Platformer · Difficult · 2D Platformer
Super Meat Boy Forever
Shared: Difficult · Precision Platformer · Platformer
Baba Is You
Shared: Difficult · Singleplayer · Indie
Timberman
Shared: Casual · Singleplayer · Difficult