Games like Nightshade
Games like Nightshade include Half-Life 2, Sonic Origins, Sonic Adventure 2, Tomb Raider I (1996), and Sonic Adventure DX. We matched them by the tags players give Nightshade on Steam (Adventure, Action, Retro, Classic, and Point & Click): closest matches first, and among equally close ones the better-known games.

Half-Life 2
Shared: Action · Classic · Adventure

Sonic Origins
Shared: Action · Adventure · Retro

Sonic Adventure 2
Shared: Action · Adventure · Classic

Tomb Raider I (1996)
Shared: Adventure · Action · Classic

Sonic Adventure DX
Shared: Adventure · Classic · Action

Grim Fandango Remastered
Shared: Adventure · Classic · Point & Click

Sonic Mania
Shared: Retro · Classic · Adventure

Indiana Jones® and the Fate of Atlantis™
Shared: Adventure · Point & Click · Classic

DuckTales: Remastered
Shared: Adventure · Action · Retro

The Curse of Monkey Island
Shared: Adventure · Point & Click · Retro

I Have No Mouth, and I Must Scream
Shared: Adventure · Point & Click · Classic

Bully: Scholarship Edition
Shared: Action · Adventure · Classic

Castlevania Anniversary Collection
Shared: Adventure · Action · Classic

Turok
Shared: Action · Adventure · Classic

The Longest Journey
Shared: Adventure · Point & Click · Classic

Day of the Tentacle Remastered
Shared: Adventure · Point & Click · Classic

The Secret of Monkey Island: Special Edition
Shared: Adventure · Point & Click · Classic

Half-Life: Opposing Force
Shared: Action · Classic · Adventure

DOOM + DOOM II
Shared: Action · Classic · Retro

Duke Nukem 3D: 20th Anniversary World Tour
Shared: Action · Classic · Retro

Tomb Raider Game of the Year
Shared: Adventure · Action

Resident Evil 4 (2005)
Shared: Action · Adventure · Classic

Monkey Island™ 2 Special Edition: LeChuck’s Revenge™
Shared: Adventure · Point & Click · Classic

The Night of the Rabbit
Shared: Adventure · Point & Click · Retro