EV Nova is an open world space game with arcade and RPG elements. It's also moddable, with Total Conversions.
Talk about the video game EV Nova, the open-world top-down space arcade shooter RPG by ATMOS and Ambrosia Software. It's the third game in the series, and the most ambitious installment to date, though Escape Velocity and EV Override are classics in their own right. Additionally, there's an upcoming remake named Cosmic Frontier.