Is Unity Free Good?

I want to know if I can make good looking games like shadow of the colosuss or borderlands 2 with unity free

I don’t know if you can make such game, but with Unity you can do almost everything. Unity pro has just some additional advanced features like realtime shaddows, postprocessing effects, …

Just have a look at the License Comparisons page. For a lot pro feature there’s a custom workaround. A “good look” is produced by the quality of models / textures / maps you provide.