GDevelop
Open Source
GDevelop is an open source game creation software.
Cocos2d-x
Open Source
Cocos2d-x is an open-source and cross platform open source free 2D game engine for mobile game development known for its speed, stability, and easy of use.
Construct 3
Commercial
Construct 3 is a game making software to develop and build games.
LibGDX
Open Source
libGDX is a free and open-source game-development application framework.
Compare GameMaker: Studio with alternatives
Compare GDevelop and GameMaker: Studio and decide which is most suitable for you.
Compare Construct 3 and GameMaker: Studio and decide which is most suitable for you.
Compare Cocos2d-x and GameMaker: Studio and decide which is most suitable for you.
Compare LibGDX and GameMaker: Studio and decide which is most suitable for you.