Games like Gummings
Games like Gummings include Portal, Portal 2, MiSide, Catherine Classic, and Call to Arms - Gates of Hell: Ostfront. We matched them by the tags players give Gummings on Steam (Strategy, Puzzle, 3D Platformer, Puzzle Platformer, and Real Time Tactics): closest matches first, and among equally close ones the better-known games.

Portal
Shared: Puzzle · Puzzle Platformer · 3D Platformer

Portal 2
Shared: Puzzle · Singleplayer · Puzzle Platformer

MiSide
Shared: Sexual Content · Singleplayer · 3D

Catherine Classic
Shared: Puzzle · Sexual Content · Puzzle Platformer

Call to Arms - Gates of Hell: Ostfront
Shared: Strategy · Real Time Tactics · World War II

Buckshot Roulette
Shared: Strategy · Singleplayer · 3D

Lost
Shared: Puzzle · Sexual Content · Strategy

Seek Girl:Fog Ⅰ
Shared: Strategy · Sexual Content · Puzzle

The Ball
Shared: 3D Platformer · Puzzle · Puzzle Platformer

Seek Girl Ⅲ
Shared: Puzzle · Strategy · Sexual Content

Quantum Conundrum
Shared: Puzzle · Puzzle Platformer · 3D Platformer

Scorn
Shared: Puzzle · Sexual Content · Nudity

Bloons TD 6
Shared: Strategy · Singleplayer · 3D

Monument Valley
Shared: Puzzle · Strategy · Singleplayer

Company of Heroes 3
Shared: Strategy · Singleplayer · Real Time Tactics

Last Train Home
Shared: Strategy · Real Time Tactics · Singleplayer

Little Nightmares II
Shared: Puzzle · Singleplayer · Puzzle Platformer

Haydee
Shared: Puzzle · Sexual Content · Singleplayer

Little Nightmares
Shared: Puzzle Platformer · Puzzle · Singleplayer

Viewfinder
Shared: Puzzle · Puzzle Platformer · Singleplayer

Lost2
Shared: Puzzle · Strategy · Sexual Content

Poppy Playtime
Shared: Puzzle · Singleplayer · Psychological Horror

Company of Heroes
Shared: Strategy · World War II · Singleplayer

Shadow Tactics: Blades of the Shogun
Shared: Strategy · Real Time Tactics · Singleplayer