Games like So Long Grandma
Games like So Long Grandma include Portal 2, Little Inferno, Garry's Mod, A Story About My Uncle, and Slime Rancher. We matched them by the tags players give So Long Grandma on Steam (Indie, Casual, First-Person, Singleplayer, and Dark Humor): closest matches first, and among equally close ones the better-known games.

Portal 2
Shared: Singleplayer · First-Person · Dark Humor

Little Inferno
Shared: Indie · Casual · Singleplayer

Garry's Mod
Shared: Casual · First-Person · Singleplayer

A Story About My Uncle
Shared: First-Person · Indie · Singleplayer

Slime Rancher
Shared: Singleplayer · First-Person · Casual

Getting Over It with Bennett Foddy
Shared: Singleplayer · Indie · Casual

Slime Rancher 2
Shared: Singleplayer · First-Person · Casual

Who's Your Daddy?!
Shared: First-Person · Casual · Dark Humor

Dead Bits
Shared: Indie · Casual · First-Person

MUSYNX
Shared: Indie · Singleplayer · Casual

Barn Finders
Shared: Casual · Indie · Singleplayer

Streamer Life Simulator
Shared: Casual · Singleplayer · Indie

Game Dev Tycoon
Shared: Indie · Casual · Singleplayer

Dark Deception
Shared: Singleplayer · First-Person · Indie

How to Make an Atomic Bomb in Your Garden
Shared: Indie · Casual · Dark Humor

Poppy Playtime
Shared: Singleplayer · First-Person · Indie

Train Station Renovation
Shared: Casual · Indie · First-Person

Moncage
Shared: Casual · Indie · Singleplayer

Plague Inc: Evolved
Shared: Indie · Singleplayer · Casual

Florence
Shared: Indie · Casual · Singleplayer

Mountain
Shared: Indie · Casual · Singleplayer

House Flipper
Shared: Singleplayer · Casual · Indie

The Stanley Parable
Shared: Indie · First-Person · Singleplayer

The Witness
Shared: First-Person · Indie · Singleplayer