The Stanley Parable - The Stanley Parable is an Action, First-person Perspective, Puzzle-Platform, Exploration and Single-player video game created and published by Galactic Cafe.
Unity - The multiplatform game creation tools for everyone.
Antichamber - "A game with half of the attention to detail and imagination Antichamber has would be a smash hit - this bare-bones first-person puzzler is one of the most thought-provoking, engaging, and challenging video games ever developed.
Godot Engine - Feature-packed 2D and 3D open source game engine.
Quantum Conundrum - Quantum Conundrum is a First-person Perspective game with strong Sci-fi, Puzzle-Platform, and Single-player elements published by Square Enix and developed by Airtight Games.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.