There’s this awesome programming language for Unreal Engine 4 called SkookumScript. Epic loved it so much that they acquired it. We loved it so much that we now maintain the language!
This is a sample project that we wrote using UE4 + SkookumScript, it is available as open source and has some decent documentation behind it. It’s a super over-engineered Space Invaders clone and is used as the test project for new versions of SkookumScript. There are also some pretty sweet assets in there for you sci-fi fans.