Godot Engine - Feature-packed 2D and 3D open source game engine.
TripleA - TripleA is a free (under GPL) turn based strategy game based on Axis & Allies board game.
Unreal Engine - Unreal Engine 4 is a suite of integrated tools for game developers to design and build games, simulations, and visualizations.
Puzzle Strike - Puzzle Strike is a Puzzle, Board, Single and Multiplayer video game created and published by Sirlin Games.
BYOND - BYOND is the premier community for making and playing online multiplayer games.
Lux Delux - Lux Delux is a game of strategy and domination inspired by the board game Risk.