Godot Engine - Feature-packed 2D and 3D open source game engine.
QICI Engine - Full-featured HTML5 game engine with visual interface for building games.
RPG Paper Maker - Website
Scroller Game Creator - Create your scroller shooter game
Construct 2 - Scirra Construct is a 2D game development engine with a focus on building games visually.
Flowlab - Flowlab is an online game creator. Make your own games to share with friends.