Games like Bastard Little Zombie
Games like Bastard Little Zombie include Celeste, LIMBO, Hollow Knight: Silksong, Braid, and Rain World. We matched them by the tags players give Bastard Little Zombie on Steam (Indie, Adventure, Difficult, Puzzle Platformer, and 2D Platformer): closest matches first, and among equally close ones the better-known games.

Celeste
Shared: Difficult · Indie · 2D Platformer

LIMBO
Shared: Indie · Puzzle Platformer · Adventure

Hollow Knight: Silksong
Shared: Indie · Difficult · Adventure

Braid
Shared: Indie · Puzzle Platformer · 2D Platformer

Rain World
Shared: Difficult · Indie · Adventure

INSIDE
Shared: Puzzle Platformer · Indie · Adventure

Hollow Knight
Shared: Difficult · Indie · Adventure

The Legend of Bum-Bo
Shared: Indie · Adventure · Strategy

UFO 50
Shared: Indie · Adventure · Strategy

SANABI
Shared: Adventure · 2D Platformer · Indie

Trine Enchanted Edition
Shared: Puzzle Platformer · 2D Platformer · Indie

Blasphemous 2
Shared: Difficult · Adventure · 2D Platformer

Squishy the Suicidal Pig
Shared: Indie · Adventure · Puzzle Platformer

Don't Starve Together
Shared: Adventure · Indie · Difficult

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

Munin
Shared: Indie · Puzzle Platformer · Adventure

Cairn
Shared: Indie · Difficult · Adventure

FTL: Faster Than Light
Shared: Indie · Strategy · Difficult

Little Nightmares
Shared: Adventure · Puzzle Platformer · Indie

Planet of Lana
Shared: Puzzle Platformer · 2D Platformer · Adventure

Noita
Shared: Difficult · Indie · Adventure

Songs for a Hero - Definitive Edition
Shared: Adventure · Indie · 2D Platformer

Creepy Tale
Shared: Adventure · Puzzle Platformer · Indie

Chrono Ark
Shared: Indie · Adventure · Strategy