Games like Millie
Games like Millie include Pikuniku, Donut County, Assemble with Care, Carto, and Florence. We matched them by the tags players give Millie on Steam (Casual, Indie, Action, Puzzle, and Cute): closest matches first, and among equally close ones the better-known games.

Pikuniku
Shared: Indie · Casual · Puzzle

Donut County
Shared: Casual · Indie · Puzzle

Assemble with Care
Shared: Casual · Indie · Puzzle

Carto
Shared: Indie · Puzzle · Cute

Florence
Shared: Casual · Indie · Cute

Slime Rancher
Shared: Cute · Adventure · Casual

The Last Campfire
Shared: Puzzle · Indie · Cute

Zuma's Revenge!
Shared: Casual · Action · Puzzle

Unpacking
Shared: Casual · Cute · Puzzle

Toki Tori
Shared: Indie · Casual · Puzzle

Planet of Lana
Shared: Action · Puzzle · Indie

Slime Rancher 2
Shared: Cute · Casual · Singleplayer

Scribblenauts Unlimited
Shared: Casual · Puzzle · Family Friendly

Puyo Puyo™ Tetris® 2
Shared: Casual · Puzzle · Action

Forward to the Sky
Shared: Action · Cute · Indie

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

Zup! S
Shared: Casual · Indie · Puzzle

Haunt the House: Terrortown
Shared: Indie · Casual · Cute

Moss VR
Shared: Puzzle · Action · Adventure

There Is No Game: Wrong Dimension
Shared: Indie · Puzzle · Casual

BEEP
Shared: Indie · Puzzle · Action

Rise of the Tomb Raider™
Shared: Action · Adventure · Female Protagonist

Muse Dash
Shared: Cute · Casual · Female Protagonist

Baba Is You
Shared: Indie · Puzzle · Cute