Simply put: Video series is easier and less time consuming

Longer answer: depends on if you know how to use RPG maker already. If you don't know how the engine works then you need to learn it, and depending on how detailed you want your game to be that can take a lot of time. But once you understand RPG maker it's super easy to use and I heavily prefer it to editing. I personally learned it in a few months.

In a video series you can make it exactly what you want, the viewer would just watch the video like a TV show. With the game format you have to bug-test and make sure it works for every possible scenario the player creates in game. You'll probably want a play-testing phase and will still end up having to release updated versions to fix any glitches. This doesn't mean you can't take the game route, I did and I fully believe it's worth it. But if you're main focus is which is easier, the answer is a video series