The contents of this package were originally part of Unity's 2D Roguelike Tutorial available at: https://www.assetstore.unity3d.com/en/#!/content/29825
Accordingly, the assets in this package "may not be resold."
The full terms are specified in the Unity FAQ (https://unity3d.com/unity/faq):
Can we use the code/art/assets in Unity Technologies' example projects?
Assets in our tutorial and example projects are well known and therefore we recommend you don't use them in commercial games and content. They are meant to be used in non-commercial content for educational purposes only. The assets may not be resold.