Limbo - “Dark, disturbing, yet eerily beautiful, Limbo is a world that deserves to be explored.” Joystiq. “Limbo is as close to perfect at what it does as a game can get.” Destructoid. Buy LIMBO: Special Edition.
Godot Engine - Feature-packed 2D and 3D open source game engine.
Contrast - A macOS app for quick access to WCAG color contrast ratios
GDevelop - GDevelop is an open-source game making software designed to be used by everyone.
Botanicula - Botanicula is a point-and-click adventure game developed by Amanita Design.
Construct 2 - Scirra Construct is a 2D game development engine with a focus on building games visually.