I get paid next week and wanna know if the game is fully 100% done before I buy 

It's a complete game. You could play from the start to the end with all necessary content and without seeing words "In development". But developer will add several new off-shoot bad endings and content for them. The first extra bad ending would appear from version 1.1.0.

In the end Star Knightess Aura is already fully functional game. I hope I didn't confuse you. 

Ok thank you, I'll get the game next paycheck