I like that it is very easy to use. You can create a lot of objects without having to learn code. It has a lot of features and you can modify it in any way you want. The only thing I don't like about this software is that it does not have a multiplayer mode. If you are looking for an alternative to Unity3d or Unreal Engine 4, then PhysicsJS is perfect! At first it was hard to get used to but as soon as you realize what each button does, it becomes second nature. There is nothing I dislike about this program. It is very user friendly. It's easy to add new functionality and I am really happy with how flexible it is.