Hi there! The short answer is that pretty much anything goes! c:
The spirit of the jam is essentially making ancient Greece something that we can all access, interrogate, or take inspiration from in whatever ways make sense to us. You could zero in on something very specific, or approach things more generally, and you're more than welcome to create something that isn't set in antiquity or that doesn't "look" Greek, in terms of how we recognize ancient aesthetics. Modern retellings, unconventional art styles, and unexpected genres (like sci-fi) are all equally welcome; the project just has to take inspiration from something Greek!