Limbo is an award-winning indie adventure, critically acclaimed for its captivating puzzle design and immersive sound and visuals. Its dark, misty spaces and haunting narrative will stay with you forever.
Hunted and alone, a boy finds himself drawn into the center of a dark project. INSIDE is a dark, narrative-driven platformer combining intense action with challenging puzzles. It has been critically acclaimed for its moody art style, ambient soundtrack and unsettling atmosphere.
If you haven't got these yet, apparently there's some issues and they have been removed from GoG so no idea if they will be removed from other platforms including Steam.