On Youtube I uploaded under cheese Kruse video a few gameplay videos, look at the case of interest.
Develop Games / Game Engine
You can even be creative. Tutorials (in German) show everything step by step. If everything is well done. To develop a little good game already takes time but can be done. In addition, you can see what a hassle behind Games and their logic is.
Through the games of the community can discover a lot. Invites you to a test;) It's much trash as well but also some really good and impressive games and ideas. I'm curious how Spark Project developed in the future.
Free 2 Play is annoying with the starter pack has everything you need first. How does this relate to time, I can not yet assess ...