I'm a little confused: does it have its own DE, or is it just a heavily modified Gnome?
Some themes are free, others (like the IMO rather complete Windows and macOS lookalike themes) require the paid version of the OS. I think that's an excellent way to get financial support for a product like this.
There are also some other nice-to-have integrations, like a pre-installed detection mechanism for certain setup.exes that will suggest Linux alternatives rather than opening them in the pre-installed Wine runtime.