Games like Big Sister
Games like Big Sister include Muse Dash, Melvor Idle, Cookie Clicker, Florence, and Keep on Mining!. We matched them by the tags players give Big Sister on Steam (Casual, Idler, 2D, Cute, and Cozy): closest matches first, and among equally close ones the better-known games.

Muse Dash
Shared: Cute · Casual · Female Protagonist

Melvor Idle
Shared: Idler · Casual · 2D

Cookie Clicker
Shared: Idler · Casual · Indie

Florence
Shared: Casual · Indie · Cute

Keep on Mining!
Shared: Idler · Casual · Indie

your wife
Shared: Casual · Cute · 2D

Zup! S
Shared: Casual · 2D · Indie

Cat Goes Fishing
Shared: 2D · Cute · Casual

Is This Seat Taken?
Shared: Casual · Cute · Cozy

Assemble with Care
Shared: Casual · Indie · Female Protagonist

Maltese's Fluffy Onsen
Shared: Casual · Cute · Idler

MyVoiceZoo
Shared: Casual · Idler · Cute

The Adventure of NAYU
Shared: Casual · Cute · 2D

Unpacking
Shared: Casual · Cute · Singleplayer

A Little to the Left
Shared: Casual · Cute · Cozy

Plants vs. Zombies GOTY Edition
Shared: Casual · 2D · Singleplayer

LEGO® Builder's Journey
Shared: Casual · Cute · Indie

Hollow Knight: Silksong
Shared: 2D · Indie · Singleplayer

Gensokyo Night Festival
Shared: Casual · Indie · Cute

Chill with You : Lo-Fi Story
Shared: Casual · Idler · Cute

Garden Galaxy
Shared: Idler · Cozy · Cute

Montaro
Shared: Casual · Cute · Indie

Slime Rancher 2
Shared: Cute · Singleplayer · Casual

Your Mother
Shared: 2D · Female Protagonist · Cute