Added Game Development Course (#7488)

* Added Game Development Course

* fix: use titles as provided by original source

Co-authored-by: David Ordás <3125580+davorpa@users.noreply.github.com>

courses/free-courses-en.md

@@ -445,6 +445,7 @@
 * [Low Poly Art For Video Games](https://www.coursera.org/learn/low-poly-art-video-games) - Andrew Dennis, Ricardo Guimaraes (Coursera)
 * [Make a Platform Shooter - GameMaker Studio 2](https://www.youtube.com/playlist?list=PL9FzW-m48fn3Ya8QUTsqU-SU6-UGEqhx6) - HeartBeast
 * [Multiplayer Shooter Tutorials - Godot](https://www.youtube.com/playlist?list=PL6bQeQE-ybqDmGuN7Nz4ZbTAqyCMyEHQa) - PlugWorld
+* [Run Bunny, Run! Creating a 2D game in Unity](https://www.youtube.com/playlist?list=PLvUqRm2B9RRBgJipfDmFR7sFhEwBn7aGT) - Rabidgremlin
 * [Unity Beginner Fundamentals](https://learn.unity.com/course/unity-beginner-fundamentals) - Pluralsight Company (Unity Learn)
 * [Unity Beginner Tutorials](https://www.youtube.com/playlist?list=PLPV2KyIb3jR5QFsefuO2RlAgWEz6EvVi6) (Brackeys)
 * [Unity User Manual](https://docs.unity3d.com/Manual/)