About this part "Your entry must include the theme of the contest. This theme is Rebirth/Rejuvenation/Resurrection." does that mean that the game MUST BE about Rebirth/Rejuvenation/Resurrection (story wise or gameplay wise) or just that it needs to include it in some major way?
Viewing post in IGMC: Rebirth FAQ
It needs to be incorporated in the game as the theme. In other words, when the judges play your game will they be able to clearly see one of those subjects as the theme of your game?
It may be helpful to read the definition of the word theme:
https://www.merriam-webster.com/dictionary/theme