Games like The Grappler
Games like The Grappler include Celeste, SANABI, Hollow Knight, Rain World, and Noita. We matched them by the tags players give The Grappler on Steam (2D Platformer, Difficult, Platformer, Physics, and Parkour): closest matches first, and among equally close ones the better-known games.

Celeste
Shared: Difficult · 2D Platformer · Platformer

SANABI
Shared: 2D Platformer · Pixel Graphics · Adventure

Hollow Knight
Shared: Platformer · Difficult · Souls-like

Rain World
Shared: Difficult · Platformer · Pixel Graphics

Noita
Shared: Physics · Difficult · Pixel Graphics

Super Meat Boy
Shared: Difficult · Platformer · 2D Platformer

Hollow Knight: Silksong
Shared: Difficult · Platformer · 2D

Blasphemous 2
Shared: Difficult · 2D Platformer · Pixel Graphics

Katana ZERO
Shared: Pixel Graphics · Platformer · 2D Platformer

Webbed
Shared: 2D Platformer · Physics · Pixel Graphics

Downwell
Shared: Platformer · Pixel Graphics · 2D Platformer

Nine Sols
Shared: Difficult · Platformer · Souls-like

SUPER CHICKEN JUMPER
Shared: Difficult · Pixel Graphics · Arcade

Dead Cells
Shared: Adventure · Pixel Graphics · Platformer

Sonic Origins
Shared: 2D Platformer · Platformer · Pixel Graphics

Blasphemous
Shared: Pixel Graphics · Difficult · Souls-like

Mina the Hollower
Shared: 2D Platformer · Pixel Graphics · Platformer

Momodora: Reverie Under The Moonlight
Shared: 2D Platformer · Pixel Graphics · Difficult

Shovel Knight: Treasure Trove
Shared: Platformer · Pixel Graphics · Difficult

VVVVVV
Shared: Platformer · 2D Platformer · Pixel Graphics

Pizza Tower
Shared: 2D Platformer · Platformer · Pixel Graphics

Rogue Legacy 2
Shared: Platformer · Arcade · Difficult

Titan Souls
Shared: Difficult · Pixel Graphics · Souls-like

Geometry Dash
Shared: Difficult · Platformer · 2D