Godot Engine - Feature-packed 2D and 3D open source game engine.
VideoScribe - Make your own whiteboard video animations with Sparkol VideoScribe – award-winning video scribing app for PC, Mac and iPad. Free trial available.
Unreal Engine - Unreal Engine 4 is a suite of integrated tools for game developers to design and build games, simulations, and visualizations.
Doodly - Create your own doodle video in just 60 seconds
BYOND - BYOND is the premier community for making and playing online multiplayer games.
TTS Sketch Maker - Create amazing whiteboard sketch videos with text-to-speech human-sounding voices in minutes!