Games like FlippUp
Games like FlippUp include Celeste, Super Meat Boy, Jump King, SANABI, and Downwell. We matched them by the tags players give FlippUp on Steam (Difficult, Indie, Precision Platformer, Action, and Platformer): closest matches first, and among equally close ones the better-known games.

Celeste
Shared: Difficult · Precision Platformer · Indie

Super Meat Boy
Shared: Difficult · Precision Platformer · Indie

Jump King
Shared: Difficult · Precision Platformer · Indie

SANABI
Shared: Action · Pixel Graphics · Indie

Downwell
Shared: Precision Platformer · Indie · Platformer

VVVVVV
Shared: Precision Platformer · Indie · Platformer

Hollow Knight
Shared: Difficult · Platformer · Indie

Rain World
Shared: Difficult · Indie · Platformer

Geometry Dash
Shared: Difficult · Precision Platformer · Platformer

Hollow Knight: Silksong
Shared: Difficult · Indie · Platformer

Shovel Knight: Treasure Trove
Shared: Platformer · Indie · Difficult

The End Is Nigh
Shared: Precision Platformer · Indie · Difficult

Rogue Legacy 2
Shared: Indie · Arcade · Action

Katana ZERO
Shared: Action · Platformer · Indie

UFO 50
Shared: Indie · Action · Pixel Graphics

Skul: The Hero Slayer
Shared: Indie · Action · Pixel Graphics

Exit the Gungeon
Shared: Indie · Action · Arcade

Nine Sols
Shared: Difficult · Platformer · Action

Out There Somewhere
Shared: Indie · Platformer · Pixel Graphics

Pizza Tower
Shared: Indie · 2D Platformer · Platformer

Volgarr the Viking
Shared: Difficult · Indie · Platformer

Hyper Light Drifter
Shared: Indie · Difficult · Pixel Graphics

Axiom Verge
Shared: Indie · Platformer · Action

Angry Video Game Nerd Adventures
Shared: Indie · Difficult · Platformer