Love2D is an excellent choice, but tutorials on it seem difficult to come by, which is very sad. I would love to see that change. Lua is a good language, and much easier to learn than Unity's C#. For beginners, I would strongly recommend Love2D over Unity. If you're more experienced, Unity offers an excellent amount of tools, however, if the game uses 2D graphics and you already know how to monetize games, I would go with Love2D for ease of use and for being open-source.