If you’re a complete novice, I wouldn’t worry too much. But you could take a look at early arcade games for inspiration–many of these games were very simple (and thus, not too hard for a beginner to implement) and since the medium hadn’t really ‘solidified’ there were lots of concepts and ideas that didn’t stick around. Some of those ideas disappeared because they were shit, mind you, but I reckon there’s still untapped potential to be found.