I don't want to slow down your enthusiasm, and what i'm about to say is based on my guess of your experience level, which i might have wrong... so take this with a grain of salt.
But if you're at the stage where you still need to learn a game engine, i would personally focus on small, but complete projects, instead of a large and complex project like a metroidvania. That's more likely to end successfully.
You can still do whatever you want anyways, if that's more fun for you... just don't feel disappointed if the deadline hits too soon... you will probably learn a lot anyways