There are many excellent online Unity resources.
As a Queen's student, you have access to Lynda.com, which has many specialized tutorials on Unity. After signing in, search for "unity".
This course has no required text. Examples of excellent resources include:
Tracy Fullerton, Game Design Workshop: A Playcentric Approach to Creating Innovative Games, Third Edition, Morgan Kaufmann, 2014.
This text provides a strong mix of theory and practical advice for game design.
Ian Millington and John Funge, Artificial Intelligence for Games, Second Edition, Morgan Kaufmann, 2009.
This is an outstanding book on AI algorithms for games, forming the foundation of AI engines.
Ian Millington, Game Physics Engine Development: How to Build a Robust Commercial-Grade Physics Engine for your Game, Morgan Kaufmann, 2012.
An excellent text on physics algorithms for games.